Only a handful of places left for our September 2026 cohort. Applications close soonApply now →

MSTA
Your future
starts here.

Circadia by Dr. Pugliese

Also known as: circadia, circadia skincare, circadia by dr pugliese, dr pugliese

Circadia by Dr. Pugliese Inc. is a US professional skincare brand founded by physician Peter T. Pugliese and organised around a chronobiology theme: environmental defence by day, repair support at night. Its UK site names Unique Skin Ltd as operator but does not publish the registered contracting distributor.

Evidence status

Manufacturer-supported

Human skin has functional circadian clocks and several barrier measures vary by time of day, but no indexed clinical trial tests a Circadia product or morning-versus-night application of the same cosmetic. The brand's mechanistic pages rely on general biology—one cited stem-cell study is in mice—and human data do not consistently support faster night repair. Product claims therefore remain manufacturer-supported despite genuine underlying chronobiology.

What Circadia is, and the ranges available#

Circadia by Dr. Pugliese Inc. is based in Leesport, Pennsylvania. Founder Peter T. Pugliese was an MD who practised family medicine before a long skincare-education career; the brand does not present him as a dermatologist. He died in 2021 aged 94. Michael Q. Pugliese has served as CEO since 2006.[12, 13, 20]

The name derives from circa dies, “around the day”. Circadia describes its philosophy as defending against environmental insult by day and stimulating repair during sleep.[12, 13]

The range includes retail cosmetics and professional back-bar systems. SWiCH uses pyruvic and succinic acids after a keratolytic preparation. Oxygen Rx generates oxygen from magnesium peroxide with an enzymatic catalyst, followed by pH-balancing steps.[14]

The former Circadia by Dr Pugliese UK Limited dissolved in 2016. Circadia UK's contact page says the brand is part of the Unique Skin family, and its privacy policy names the site operator as “Unique Skin Ltd”. Unique Skin's own terms identify Unique Skin Limited (09713343) of Hitchin and its portfolio includes Circadia, but Circadia UK's site publishes no company number or distribution agreement; the exact contracting distributor should be confirmed from invoices or product documentation.[15][12, 15, 21]i

Use of Circadia in aesthetic practice#

Circadia products are cosmetics in GB. They require a Responsible Person, Cosmetic Product Safety Report, SCPN notification and compliant labelling; professional-only back-bar status does not create an exemption.[17, 18]

Cosmetic claims must meet the assimilated common criteria and remain within the evidence held. Terms such as “germicidal”, rosacea treatment or ATP-driven repair require especially careful presentation because they may exceed cosmetic evidence or move towards medicinal presentation.[14][18]

Oxygen Rx raises a specific composition question. Annex III caps skin products at 4% hydrogen peroxide present or released. Magnesium peroxide is not named, so the relevance arises through released H2O2; the safety file should establish that figure.[14, 17]i

England's peel tiers remain a proposal. The 2023 document placed superficial peels in green, medium depth in amber and deep phenol peels in red, while the 2025 response deferred allocation.[19]

Contraindications and cautions#

The exact product and treatment instructions govern. Retail skincare, pyruvic/succinic acid systems and peroxide-releasing treatments do not share one contraindication profile.

SWiCH's acid concentrations and pH are not public. Its manufacturer calls it an alternative to a peel, but pyruvic acid is a recognised potent peel agent. It should therefore be assessed by composition, penetration and intended depth rather than the marketing category.[11, 14]

Oxygen Rx requires confirmation of released peroxide, suitability for the skin presentation and clarity about vascular claims. Its own training material describes it as both vasoconstricting and stimulating new blood vessels, which are not compatible explanations for rosacea.[14]

Medical diagnoses, active infection, dermatitis and unexpected vascular or pigment presentations are not resolved by a proprietary treatment label.

Clinical uses and the evidence behind them#

Circadian biology

Human keratinocytes, melanocytes and fibroblasts have functional clock machinery with cell-specific phases, and hPer1, hCry1 and hBmal1 cycle in human skin biopsies. Cultured epidermal stem cells also show phased readiness for proliferative and differentiation signals.[3, 4, 10][5]i

TEWL, surface pH and temperature show rhythmicity at forearm, forehead and shin, with higher permeability in evening and night; stratum-corneum hydration did not show significant rhythm.[1]

Barrier recovery after forearm tape stripping was significantly slower between 20:00 and 23:00 than at other tested times. Human epidermal mitosis has not shown one reproducible nightly peak: some experiments found afternoon or 21:00 peaks and others did not.[8, 9][2]

Human minimal erythema dose also varies by time, with greater UV tolerance in the morning. A much-cited cancer-timing experiment was in nocturnal hairless mice and cannot transfer clock times directly to people.[7][6]

Product evidence

No peer-reviewed Circadia product trial was identified. Peter Pugliese's six indexed papers include no circadian-rhythm research or Circadia trial.[16][16]

The US science page provides no references; the UK page cites three mechanistic papers, none testing a product, and presents one mouse result without naming the species.[12, 13]

SWiCH and Oxygen Rx

SWiCH's proposed ATP mechanism and outcome have not been demonstrated in a published product trial. Pyruvic acid can produce peel effects; a separate 50% pyruvic-acid study reported comfort and no PIH, showing that low downtime does not decide whether chemistry is a peel.[11, 14]

No product trial establishes Oxygen Rx's rosacea, oxygenation or germicidal outcomes. Internal inconsistency in the vascular rationale further limits a confident mechanism claim.[14]

Selecting a Circadia product#

Selection separates a plausible timing concept from the finished formula. Ingredient list, concentration, pH, vehicle, released peroxide, intended purpose, comparator and product-specific evidence carry more weight than AM or PM branding.

No study establishes that the same cosmetic active produces a better human clinical outcome at night than in the morning. This is untested rather than disproved. Timing may still affect tolerance or routine adherence; it cannot be claimed as demonstrated efficacy.[no source found]

For SWiCH and Oxygen Rx, the distributor should provide the current instructions, full safety documentation and composition information necessary for competence and insurance decisions. Skinipedia does not publish a proprietary-treatment protocol.

Adverse effects and their management#

Acid-system responses

Pyruvic and keratolytic systems may produce stinging, erythema, desquamation or pigment change depending on concentration, pH and depth. Circadia's undisclosed SWiCH concentrations prevent independent depth assessment.[11, 14]

Peroxide-system responses

Peroxide-releasing systems may cause irritation or chemical injury if formulation, activation or exposure differs from the safety assessment. Product incidents require retention of lot, components and mixing record.[14, 17]

Persistent reactions

Blistering, escalating pain, infection, delayed healing, progressive pigment or vascular change and systemic symptoms require cessation and appropriate clinical assessment.

Referral and scope boundaries#

Rosacea is a medical diagnosis. Persistent facial erythema, papules, pustules, ocular symptoms or uncertain vascular change should be referred rather than treated on the strength of Oxygen Rx claims.

Suspected infection, dermatitis, significant peel injury or a presentation outside cosmetic scope requires referral. Brand training does not substitute for diagnosis or an external competence standard.

Mechanism of action#

Circadian clocks coordinate gene expression and cellular responses across the day. Human skin shows measurable rhythms, but different endpoints peak at different times and some findings conflict.[1, 2, 3, 4, 5, 8, 9, 10]

SWiCH proposes that pyruvic and succinic acids increase Krebs-cycle ATP and repair. A simpler competing explanation is ordinary alpha-keto-acid exfoliation or controlled injury; no product trial distinguishes them.[11, 14]

Commonly misstated claims#

“Skin regenerates fastest from 11 pm to 4 am”

No primary human evidence establishes that window, and mitotic studies are inconsistent.[8, 9]

Supported statement: human epidermal activity varies over the day, without one validated universal repair window.

“Night is when barrier repair accelerates”

One human tape-strip study found recovery slowest from 20:00 to 23:00, while permeability was higher in evening and night.[1, 2]

Supported statement: barrier function varies diurnally, but the pattern is not simply “repair at night”.

“Circadia's timing claims are product-tested”

The brand cites mechanistic studies, not a Circadia product or morning-versus-night trial.[12, 13, 16]

Supported statement: circadian skin biology is real; clinical benefit from Circadia timing remains untested.

“SWiCH is not peel chemistry”

It uses pyruvic acid after a keratolytic preparation, and dermatology literature describes pyruvic acid as a potent peel agent.[11, 14]i

Supported statement: SWiCH is a proprietary acid system whose depth cannot be established publicly because concentration and pH are undisclosed.

Areas of remaining uncertainty#

  • No human trial compares morning with evening use of the same cosmetic; this prevents a timing-efficacy claim.
  • Human DNA-repair phase is not established from the mouse UV model; this prevents transferring mouse clock times.
  • SWiCH concentrations and pH are undisclosed; this prevents public depth classification and future tier mapping.
  • Oxygen Rx's released H2O2 concentration is not public; this means compliance rests on the safety file.
  • Circadia UK publishes the “Unique Skin Ltd” operator name but not a company number or distribution agreement; the exact contracting entity requires confirmation from invoices and product documentation.

Frequently asked questions#

Is Circadia founded by a dermatologist?

No primary brand source describes Peter Pugliese as one; it says he practised family medicine.[12, 20]i

Do night products work better because skin repairs at night?

No product trial establishes that. Skin rhythms exist, but barrier and mitotic findings are more complex.[1, 2, 8, 9]

Is SWiCH a peel?

It uses recognised peel chemistry, but its undisclosed concentration prevents precise depth classification.[11, 14]

Is Oxygen Rx approved to treat rosacea?

No cosmetic approval establishes that disease claim. Rosacea requires diagnosis and product claims must remain within cosmetic evidence.[14, 18]

What protocol applies?

The current instructions for the exact Circadia product govern. Skinipedia does not publish a generic substitute.

References#

Each source is graded by evidence tier. Tier 4 material (manufacturer documents, expert consensus, practitioner experience) is useful for protocol and context, and is never presented as equivalent to independent clinical evidence.

  1. Yosipovitch G, Xiong GL, Haus E, Sackett-Lundeen L, Ashkenazi I, Maibach HI. Time-dependent variations of the skin barrier function in humans: transepidermal water loss, stratum corneum hydration, skin surface pH, and skin temperature. J Invest Dermatol. 1998;110(1):20-23.Tier 3Supports: In vivo human chronobiology study. 16 healthy volunteers (9 men, 7 women, aged 23-53), sampled every 2 hours in two sessions across a 24-hour span, 12 samples per variable at forehead, forearm, upper back and shin. Cosinor analysis plus ANOVA. Statistically significant circadian rhythmicity found in transepidermal water loss, skin surface pH and skin temperature at forearm, forehead and shin; NO significant rhythm in stratum corneum hydration. Authors' conclusion: 'These results suggest that skin permeability is higher in the evening and night than in the morning.' Scope limits: small single-centre sample, healthy adults only, no clinical endpoint, no product tested, and higher night-time TEWL indicates a leakier barrier rather than better repair.
  2. Denda M, Tsuchiya T. Barrier recovery rate varies time-dependently in human skin. Br J Dermatol. 2000;142(5):881-884.Tier 3Supports: Human volunteers, volar forearm tape-stripped at different clock times, barrier recovery measured as TEWL 1 hour after stripping. 'The barrier recovery rate was significantly lower between 20:00 h and 23:00 h than that at other time points.' Skin surface temperature and basal TEWL reached their highest values at about 03:00 (33.6 degrees C; 0.30 mg/cm2/h); salivary cortisol was highest at 09:00 (7.8 pmol/mL). The authors state the results 'suggest' time-dependent variation in barrier repair independent of skin temperature and cortisol - a suggestion, not a demonstrated independence. Scope limits: subject number not stated in the abstract, acute tape-strip model on volar forearm rather than a facial or clinical outcome, single site, 1-hour recovery window only. Directly relevant because it is the opposite of the marketing intuition that barrier repair is at its best in the late evening.Funding / interest: Conducted at Shiseido Research Center 2, Yokohama - the affiliation recorded in the PubMed record for the corresponding author (Denda M), a cosmetics manufacturer. The PubMed record does not carry an affiliation for Tsuchiya T, so the second author's employer is not independently confirmed here.
  3. Bjarnason GA, Jordan RC, Wood PA, Li Q, Lincoln DW, Sothern RB, Hrushesky WJ, Ben-David Y. Circadian expression of clock genes in human oral mucosa and skin: association with specific cell-cycle phases. Am J Pathol. 2001;158(5):1793-1801.Tier 3Supports: Serial biopsies of oral mucosa and skin across one 24-hour period in 8 healthy, diurnally active male volunteers. hClock, hTim, hPer1, hCry1 and hBmal1 all expressed in oral mucosa and skin; hPer1, hCry1 and hBmal1 were rhythmic, peaking early in the morning, in late afternoon and at night respectively, whereas hClock and hTim were NOT rhythmic. In concurrent ORAL MUCOSA biopsies (not skin), thymidylate synthase activity, a marker for DNA synthesis, showed circadian variation peaking in early afternoon, coinciding with S-phase timing from the group's earlier work; the major hPer1 peak coincided with the G1 peak in oral mucosa, which the authors read as 'a possible link between the circadian clock and the mammalian cell cycle'. That link is a genuine positive finding for the chronobiology premise. Scope limits: 8 men, one 24-hour cycle, gene expression rather than clinical outcome, and both the proliferation marker and the cell-cycle phasing were measured in oral mucosa rather than skin.
  4. Sandu C, Dumas M, Malan A, Sambakhe D, Marteau C, Nizard C, Schnebert S, Perrier E, Challet E, Pevet P, Felder-Schmittbuhl MP. Human skin keratinocytes, melanocytes, and fibroblasts contain distinct circadian clock machineries. Cell Mol Life Sci. 2012;69(19):3329-3339.In vitroTier 3Supports: Primary cultures of fibroblasts, keratinocytes and melanocytes established from a single abdominal biopsy from one donor; clock-gene expression assessed by qPCR after dexamethasone synchronisation, with a purpose-built mathematical method fitting up to nine clock genes to a common period. Demonstrates functional circadian machinery in each of the three cell types, with cell-type-specific periods and phase relationships. Scope limits: cell culture, one donor, pharmacologically synchronised; shows that the clock exists in these cells, not that it governs any clinical outcome and not that any topical product interacts with it.Funding / interest: Five of the eleven authors (Dumas, Marteau, Nizard, Schnebert, Perrier) were employed by LVMH Recherche alongside CNRS/University of Strasbourg co-authors, and the work was supported by LVMH Research and the CNRS, with cell-culture technical assistance acknowledged to LVMH Research. LVMH is a cosmetics manufacturer. No formal conflict-of-interest statement is printed.
  5. Janich P, Toufighi K, Solanas G, Luis NM, Minkwitz S, Serrano L, Lehner B, Benitah SA. Human epidermal stem cell function is regulated by circadian oscillations. Cell Stem Cell. 2013;13(6):745-753.In vitroTier 3Supports: In cultured human epidermal stem cells and their differentiated progeny, core clock genes peak in successive, phased waves that establish distinct temporal intervals across a 24-hour period; each wave associates with peak expression of transcript subsets that temporally segregate the cells' predisposition to respond to proliferation or differentiation cues such as TGF-beta and calcium. Circadian arrhythmia 'profoundly affects stem cell function in culture and in vivo'. Scope limits: the human work is cell culture; the in vivo arrhythmia work is mouse. The paper's own framing of clock disruption contributing to ageing and carcinogenesis is explicitly stated as a hypothesis.
  6. Gaddameedhi S, Selby CP, Kaufmann WK, Smart RC, Sancar A. Control of skin cancer by the circadian rhythm. Proc Natl Acad Sci U S A. 2011;108(46):18790-18795.Animal studyTier 3Supports: MOUSE study in SKH-1 hairless mice. The rate-limiting nucleotide excision repair subunit XPA and the excision repair rate show daily rhythmicity in mouse skin, 'with a minimum in the morning and a maximum in the afternoon/evening'. Mice irradiated with UVR at 04:00 showed decreased tumour latency and about a fivefold increased multiplicity of invasive squamous cell carcinoma compared with mice irradiated at 16:00. The authors conclude time of day of UVR exposure contributes to carcinogenicity 'in mice, and possibly in humans'. Scope limit that matters: mice are nocturnal, so the phase relationship to a diurnal human is not established by this work, and the human-equivalent clock time for 04:00 in a nocturnal animal is not simply 04:00.
  7. Damiani G, Pacifico A, Scoditti E, et al. Circadian Oscillations of Minimal Erythema Dose (MED) are Also Influenced by Diet in Patients with Psoriasis: A Chronomedical Study. Dermatol Ther (Heidelb). 2023;13(10):2229-2246.Tier 3Supports: Two-phase cohort study. Phase 1: 54 omnivorous psoriasis patients and 54 matched healthy controls; MED measured morning, afternoon and evening, before and after a narrowband-UVB course. MED differed significantly across the three time points in both groups, before and after phototherapy (p < 0.001). Phase 2: 144 psoriasis patients on six different diets; MED oscillations persisted after clearance and were influenced by both diet type and time of day (p < 0.001); vegans had the lowest MED values, Ramadan fasting the highest. Authors conclude patients with lower MEDs 'should be preferentially treated in the morning when the MED is higher'. Scope limits: single-country cohort, psoriasis-weighted, artificial NB-UVB source, and MED is a sunburn threshold rather than a photoageing or product endpoint. Authors declare no conflict of interest.
  8. Camplejohn RS, Gelfant S, Chalker D, Sittampalam Y. Mitotic and labelling activity in normal human epidermis in vivo. Cell Tissue Kinet. 1984;17(4):315-322.Tier 3Supports: Epidermal biopsies from 28 young men. Mean labelling index 5.5%, mean mitotic index 0.06%, with individual mitotic indices ranging from 0.002% to 0.438%. In the first two of three experiments comparing 09:00 with 15:00, mitotic index was 2.6-fold higher at 15:00 (p < 0.001); in the third experiment no difference was found, 'suggesting that the timing and occurrence of diurnal rhythms of mitotic activity may not be consistent in normal human epidermis'. IMPORTANT COUNTERPOINT: in the single experiment that tested 21:00, mitotic index was significantly higher at 21:00 than at either 09:00 or 15:00 - a real, if isolated, evening peak. Labelling index did not vary by time of day but did vary seasonally, peaking in July and troughing in January. Median ratio of labelled to mitotic cells 98:1. Scope limits: young male subjects, small biopsy-based indices with very high variance, dated methodology, and single-experiment findings at each time point.
  9. Gelfant S. 'Of mice and men' the cell cycle in human epidermis in vivo. J Invest Dermatol. 1982;78(4):296-299.Tier 4Supports: Comparative review with accompanying original DNA-labelling and mitotic-index experiments in human and mouse epidermis. States verbatim: 'In contrast to mouse epidermis, there are no consistent diurnal fluctuations in and there is no cell kinetic relationship between mitotic and DNA-labeling indices in normal human epidermis in vivo.' Adds that inter-individual variability and the absence of cell-cycle-related circadian fluctuation 'may preclude the use of circadian rhythmicity for therapy scheduling'. Scope limits: 1982, pre-molecular-clock era, and it predates the discovery of the peripheral clock machinery; it speaks to epidermal proliferation kinetics, not to whether clock genes cycle.
  10. Salazar A, von Hagen J. Circadian Oscillations in Skin and Their Interconnection with the Cycle of Life. Int J Mol Sci. 2023;24(6):5635.Tier 4Supports: Narrative review of molecular clock machinery in skin, its link to cutaneous immunology and homeostasis, the interplay of circadian with seasonal rhythms, and lifespan changes. Notes that 'recent reports indicate that light can independently entrain peripheral circadian clocks, challenging the currently prevalent hierarchical model', and states that a comprehensive overview of these processes in skin was lacking. Not a systematic review: no protocol, search strategy or risk-of-bias assessment. Provides no product-level evidence.Funding / interest: Both authors are employees of Merck KGaA, Darmstadt, and the paper carries an explicit conflict-of-interest statement saying so; von Hagen additionally lists University of Applied Sciences Giessen and ryon-GreenTech Accelerator Gernsheim. Merck KGaA supplies personal-care and cosmetic ingredients, a commercial interest in the chronobiology-of-skin narrative.
  11. Berardesca E, Cameli N, Primavera G, Carrera M. Clinical and instrumental evaluation of skin improvement after treatment with a new 50% pyruvic acid peel. Dermatol Surg. 2006;32(4):526-531.Tier 3Supports: Open-label, uncontrolled study in 20 otherwise healthy subjects with photodamage, superficial scarring and melasma; four peeling sessions at 2-week intervals with a 50% pyruvic acid formulation (pyruvic acid 50%, dimethyl isosorbide, propylene glycol, ethyl alcohol, dimethyl sulfone, ethyl lactate, water). Instrumental evaluation showed significant reduction in pigmentation in melasma, significant increase in skin elasticity and improved wrinkling; no persistent erythema and no post-inflammatory hyperpigmentation. Establishes the pharmacology point that matters here: pyruvic acid is 'an alpha-keto acid that presents keratolytic, antimicrobial, and sebostatic properties as well as the ability to stimulate new collagen production and elastic fibers formation', and 'because of its low pKa and its small dimension, it penetrates rapidly and deeply through the skin, so far as to be considered a potent chemical peel agent'. The paper's background states that pyruvic acid application 'usually induces intense burning' with post-peel erythema, desquamation and sometimes crusting - but that is precisely what this study set out to solve, and its own RESULT was that patients 'did not report any discomfort either during the peeling session or during the postpeeling period'. Read honestly, the paper says a well-formulated 50% pyruvic peel can be comfortable; it does not say pyruvic acid stops being a peel when it stops stinging. Scope limits: n=20, no control arm, no blinding, a single proprietary vehicle, and it tells us nothing about Circadia's undisclosed pyruvic acid concentration.Funding / interest: No funding statement in the PubMed record; authors affiliated to Dermatological Institute S. Maria e S. Gallicano, IRCCS, Rome. The study evaluates a specific proprietary 'new non-erythematogenic formulation', so a manufacturer interest cannot be excluded.
  12. Circadia UK (circadiaskin.co.uk). About page (including its References section), Contact page, and the 'Oxygen Rx Treatment' and 'SWiCH Dermal Rejuvenation System' treatment pages. Accessed 2 August 2026.Tier 4Supports: The UK distributor's own words. Positioning verbatim: 'At Circadia UK, our philosophy of skincare is centered on the body's circadian rhythms, defending from environmental insult during the day, and stimulating repair mechanisms during sleep.' Brand name derived from 'the two Latin words circa dies, meaning around the day'. Biography verbatim: 'Peter T. Pugliese, MD practiced family medicine before dedicating over 40 years to the science of skin and aging', authored 'the 2005 landmark text, Advanced Professional Skin Care, Medical Edition', and is called 'the most honored and beloved educator in the professional skin care industry'; Michael Q. Pugliese 'became the third-generation CEO of Circadia by Dr. Pugliese, Inc. in 2006' (the page says third-generation; it does not state the family relationship). CORRECTION TO AN EARLIER READING OF THIS SOURCE: the About page DOES carry a References section, listing three papers - Janich P et al., 'The circadian molecular clock creates epidermal stem cell heterogeneity', Nature 2011 (a mouse study, PMID 22080954); Geyfman M, Andersen B, 'How the skin can tell time', J Invest Dermatol 2009; and Yosipovitch G et al., J Invest Dermatol 1998 (source 1 here). None of the three tests a Circadia product, and the surrounding copy reads 'A recent study reveals the importance of the biological clock in the regeneration of skin stem cells. When this system is disrupted it results in premature tissue aging, as well as a greater predisposition to developing skin tumours' - a mouse result stated without species. The Oxygen Rx treatment page lists indications 'Acne, Rosacea, sun-damaged skin, telangiectasia' and claims 'Germicidal action to the skin', 'A skin lightening agent, improves scars and lightens sun damage', 'Increases skin function', 'Decreases erythema', 'Vasoconstricting' and 'Stimulates fibroblasts', with no ingredient list and no references. The SWiCH treatment page calls it a 'unique alternative to chemical peels that takes advantage of the skin's natural repair mechanism without causing damage', says 'it is now possible to achieve repair of the skin without having to induce tissue damage' and promises 'Little downtime following treatment', naming kit components (Hydrating Cleanser, EpiPrep, Cellular SWiCH, Fraction V, Vitamin Veil Cleanser) but no actives or concentrations and no references. Contact page states 'Circadia by Dr Pugliese is part of the Unique Skin family in the UK', phone 01462 481500, email info@uniqueskin.co.uk. No UK company number, registered address or Responsible Person is published on the site.Funding / interest: Distributor marketing material; the publisher sells the products described and has a direct commercial interest in every claim on the page.
  13. Circadia by Dr. Pugliese Inc. (circadia.com). Home page, 'The Science of Circadia' and Terms of Service. Accessed 2 August 2026.Tier 4Supports: Corporate identity from the Terms of Service: 'Circadia by Dr. Pugliese Inc.', 1025 James Dr, Leesport, PA 19533, hello@circadia.com. Brand strapline 'Science & Nature in Perfect Rhythm' and 'Innovative Skincare Based on Your Circadian Rhythm', with a day/night split: daytime protection against UV, pollution and oxidative damage; night-time regeneration, recovery and barrier restoration. Science page claims verbatim: 'Circadian rhythms influence everything from cell regeneration to the skin's ability to absorb treatment products'; 'Disruptions in these rhythms can lead to premature aging, increased susceptibility to skin conditions, and reduced efficacy of skincare treatments'; 'At Circadia, we leverage the science of chronobiology... to create products that align with these natural cycles'. Critically, the page cites no studies, journals or references of any kind, and names Dr Pugliese's 'groundbreaking research into circadian rhythms' without identifying a single publication.Funding / interest: Brand-owned marketing material; the publisher manufactures and sells the products described.
  14. Circadia. 'Oxygen Rx Treatment / SWiCH Dermal Rejuvenation System' professional workshop slide deck, CIRCADIA(R) 2020, copyright 2018 (PDF, 6 pages). Retrieved from circadia.com.ua.Tier 4Supports: Circadia's own practitioner training deck (6 slides-per-page pages, slide footers 'CIRCADIA(R) 2020', copyright notice 'Copyright 2018', print date 4/23/20), and the only document found that names actives. Oxygen Rx protocol steps: 'Step 1A- Deionized Water (Gel)', 'Step 1B - Magnesium Peroxide (Powder)', 'Step 2- Enzyme Activator- Enzymatic Catalyst that splits oxygen and Water (Spray)', 'Step 3- PH Equalizer-Quenches out oxygen before creating damage', 'Step 4- Citric Spray- Rebalances pH of skin'. Claimed actions of oxygen: 'Reduces Edema', 'Inhibits lipid peroxidation', 'Enhances antibacterial activity', 'Stimulates fibroblast activity', 'Affects vascularization', and in ageing 'Breaks the bonds that hold the cells together - proteolytic oxidation'. SWiCH: 'The two main ingredients in the SWiCH solution are two of the Krebs Cycle intermediates' - 'Pyruvic acid', 'Succinic acid' - 'Using these two components will accelerate the action of the cycle and produce more ATP. Amounts and penetration are critical to success. The solution reaches deep into the skin without damaging the epidermis.' Also 'Simple to apply, easily tolerated, and no downtime.' Kit: Hydrating Cleanser, EpiPrep ('A keratolytic solution to enhance penetration'), Cellular SWiCH Solution ('Alpha-Keto Acids designed to stimulate cellular energy (ATP)'), Fraction V post-peel lotion (EUK 134, Pepha-active microalgae extract, Lipochroman 6). SWiCH indications: 'Aging, Mature, Hyperpigmentation'. SWiCH contraindications listed verbatim: 'Allergy to aspirin/citric acid, pregnant/Nursing, Accutane use within past year, younger skins, Retinol/Glycolic (Have client pull off for 2 weeks), Oily, Acne, Rosacea'. Internally inconsistent rosacea claims for oxygen: 'Vasoconstricting - Reduces Redness' alongside 'Increases skin function stimulating endothelial cells to make new blood vessels.' No concentration, pH, reference or study appears anywhere in the deck.Funding / interest: Brand training material published by the manufacturer for practitioners it sells to; no independent authorship or peer review.
  15. Companies House (Register of Companies for England and Wales). Records for CIRCADIA BY DR PUGLIESE UK LIMITED (09062586) and UNIQUE SKIN LIMITED (09713343). Accessed 2 August 2026.Tier 4Supports: CIRCADIA BY DR PUGLIESE UK LIMITED, company number 09062586, private limited company, registered office 16 Sandringham Gardens, Ilford, Essex IG6 1NY, incorporated 29 May 2014, DISSOLVED 5 January 2016; SIC code never filed ('To be provided on next annual return'). There is therefore no live UK company trading under the Circadia brand name. UNIQUE SKIN LIMITED, company number 09713343, active, incorporated 31 July 2015, registered office Unit 1 The Cam Centre, Wilbury Way, Hitchin, Herts SG4 0TW - the Hitchin location matching the 01462 dialling code published by Circadia UK - SIC 86900 'Other human health activities', which is a health-services code rather than a wholesale or distribution one. Note: the register does not itself record any distribution relationship; the link between the trading name 'Unique Skin' on circadiaskin.co.uk and this specific registered company is inferred from name and locality, not confirmed by a filing.
  16. NCBI PubMed/MEDLINE records for Circadia products and Peter T. Pugliese as author. Accessed 2 August 2026.Tier 4Supports: Author search 'Pugliese PT[Author]' returns exactly 6 records, verified individually: 'The pathogenesis of cellulite: a new concept' (J Cosmet Dermatol 2007, no abstract); 'The skin's antioxidant systems' (Dermatol Nurs 1998); 'Some biological actions of alkylglycerols from shark liver oil' (J Altern Complement Med 1998); 'The skin, free radicals, and oxidative stress' (Dermatol Nurs 1995); a co-authored surfactant barrier study (Borroni et al., Br J Dermatol 1986, no abstract); and a 1968 berylliosis serology paper (Arch Environ Health). None concerns circadian rhythm or chronobiology; none is a randomised or controlled trial; none tests a Circadia product. Searches for 'Circadia skin care peel' and 'Circadia AND cosmetic' return 0 records. A bare 'Circadia' search returns 15 records, all unrelated to skincare - predominantly the Circadia contactless respiratory/sleep monitoring device (Lauteslager et al.) and an unconnected home-based melatonin study called the Circadia Pilot Study, plus older papers matched on 'circadia' as a word fragment. Conclusion: no peer-reviewed clinical evidence for any Circadia skincare product is indexed in PubMed.
  17. Regulation (EC) No 1223/2009 of the European Parliament and of the Council on cosmetic products, as assimilated into GB law, Annex III entry 12; enforced in Great Britain by the Cosmetic Products Enforcement Regulations 2013 (SI 2013/1478).Tier 1Supports: Annex III entry 12 covers 'Hydrogen peroxide and other compounds or mixtures that release hydrogen peroxide, including carbamide peroxide and zinc peroxide'. Maximum concentration in ready-for-use preparation: hair products 12% H2O2 (40 volumes) present or released; SKIN PRODUCTS 4% of H2O2, present or released; nail hardening products 2%; oral products 0.1%; tooth whitening above 0.1% and up to 6% restricted to dental practitioners; eyelash products 2%, professional use only. The Cosmetic Products Enforcement Regulations 2013 (SI 2013/1478) create the GB offences and enforcement powers for breaches of the Cosmetics Regulation, with market surveillance carried out by enforcement authorities. Scope note: the 4% skin cap is expressed as H2O2 present OR RELEASED, so peroxide-generating salts fall within it; the entry does not name magnesium peroxide explicitly, and whether a specific product complies depends on its released-H2O2 figure, which is not published.
  18. Commission Regulation (EU) No 655/2013 laying down common criteria for the justification of claims used in relation to cosmetic products, as assimilated into GB law.Tier 1Supports: Retained/assimilated direct EU legislation in GB as at IP completion day. Sets six common criteria that every cosmetic claim must meet: legal compliance, truthfulness, evidential support, honesty, fairness, and informed decision-making. Claims for cosmetic products must be justified by adequate and verifiable evidence, and 'presentations of a product's performance shall not go beyond the scope' of the available supporting evidence. Applies to professional back-bar products and practitioner-facing marketing, not only consumer packaging.
  19. Department of Health and Social Care. The licensing of non-surgical cosmetic procedures in England: consultation document. 2023.Tier 1Supports: PROPOSAL ONLY, not law; the consultation closed at 11:59pm on 28 October 2023. Sets out a proposed three-tier green/amber/red model. Green tier includes 'chemical peels that involve destruction only into viable epidermis (the outermost layer of the skin)'. Amber tier covers 'medium depth peels that involve full thickness destruction of entire epidermis into upper dermis', with TCA at 35-50% given illustratively. Red tier covers 'deeper chemical peels such as phenol peels'. No scheme is in force; tier placements exist only in this 2023 consultation document. The government response published 7 August 2025 does not assign individual procedures, saying instead that responses highlighted 'where further work is needed to determine specific procedures' classification within the scheme' and committing to a further public consultation.
  20. Bean Funeral Homes & Cremation Services. Obituary: Peter Pugliese, MD. Reading, Pennsylvania. January 2021.Tier 4Supports: Records Peter Thomas Pugliese, MD, died 15 January 2021 aged 94, having begun his career as a physician in 1957. States he held 13 patents, authored hundreds of industry publications, and received the Mason G. deNavarre Medal Award, 'The American Society of Cosmetic Chemists highest honor', in 1996. On the brand: 'nearly 50 years after beginning his career as a physician' he founded 'Circadia by Dr. Pugliese, a skincare system based on the circadian rhythms of the body and the science of chronobiology' (an earlier draft of this entry paraphrased this as 'a skincare line grounded in circadian biology' - corrected to the printed wording). The obituary also repeats the brand's marketing line that Circadia became 'the first product manufacturer to introduce topical ingredients proven to work with the body's natural circadian rhythms' - an unevidenced commercial claim reproduced in a memorial notice, not an independent finding. It does not describe him as a dermatologist. Scope limit: an obituary is a family/industry notice, not a verified record; it does not give a founding year for the company.
  21. Circadia UK privacy policy; Unique Skin Ltd terms and conditions, company story and Circadia collection. Accessed 4 August 2026.Tier 4Supports: Circadia UK's privacy policy identifies the website operator as 'Unique Skin Ltd' and uses info@uniqueskin.co.uk. Unique Skin's own terms identify UNIQUE SKIN LIMITED, company number 09713343, at Unit 1 The Cam Centre, Hitchin SG4 0TW; its story page names Circadia in its commercial portfolio and its Circadia collection offers the products for sale. Scope limit: Circadia UK's site does not publish that company number or a distribution agreement, so mapping its 'Unique Skin Ltd' operator to registered company 09713343 and calling that entity the contracting distributor remains an inference rather than a direct statement.Funding / interest: Commercial websites operated by the business selling the products. They establish published identity and trading activity, not independent verification or a distribution contract.