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Tranexamic acid

Also known as: TXA, tranexamic, tranexamic acid serum, Cyklokapron

Tranexamic acid is an antifibrinolytic medicine also used for melasma by oral, topical and intradermal routes. Oral use for melasma is off-label and prescriber-led. Topical formulations beat vehicle and match hydroquinone in trials, but recurrence after stopping is common by any route.

Evidence status

Moderate

Moderate-to-high for short-term topical use in melasma against vehicle, and moderate for equivalence with hydroquinone with fewer adverse events. Moderate for short-term oral use in selected patients. Durable remission after stopping, rare-event safety in months-long regimens, and efficacy for PIH all remain insufficiently established.

What tranexamic acid is, and the routes available#

Tranexamic acid is an antifibrinolytic medicine — it interferes with the breakdown of blood clots, which is why it is licensed in the UK for bleeding indications such as heavy menstrual bleeding and haemorrhage. Melasma is not a licensed indication for the oral tablet.[1]

Its use in pigmentation is a second life for the molecule, and the category is defined by route rather than by ingredient. The same molecule applied topically, taken orally or injected into the skin carries three different bodies of evidence, three legal positions and three risk profiles. More than almost any other active, tranexamic acid cannot usefully be discussed as one thing.

RouteUK status for melasmaEvidence
TopicalCosmetic formulations availableTwo systematic reviews reach different conclusions
OralOff-label prescribingShort-term benefit; relapse reported after stopping
IntradermalOutside the injectable's licensed routeLimited; not a licensed use

Use of tranexamic acid in aesthetic practice#

The oral tablet is a prescription-only medicine and melasma is not a licensed indication for it, so oral use for pigmentation is off-label prescribing. That is entirely lawful, and it places responsibility on the prescriber for the evidence base, for explaining the off-label status, and for monitoring and follow-up.[1, 2]

Prescribing belongs to an appropriately qualified prescriber acting within their competence — the MHRA guidance names doctors, dentists, independent nurse and pharmacist prescribers and specified other prescribers. “Aesthetic practitioner” is not a legal prescribing category: some hold that authority and some do not. Discussing the evidence and supporting a referral is neither supply nor prescribing, so you can do both for a client who is considering it; selling or supplying a prescription-only medicine outside a lawful route is a different matter.[2]

Topical cosmetic preparations

Topical cosmetic formulations are available, and they are the part of the category within an aesthetic practitioner’s scope to recommend and to retail. What that scope covers is the preparation rather than the evidence: which formulation the published results belong to is a separate question, and it is the one that decides whether a given product has anything behind it.

The injectable and intradermal routes

The UK injectable product is licensed for slow intravenous use only, which places intradermal delivery for melasma outside its licensed route.[11]

Contraindications and cautions#

Pregnancy

Pregnancy data for systemic tranexamic acid covers roughly 230 reported exposures, mostly acute late-pregnancy use for medical indications. Within that data, no increase in malformations has been reported, and animal studies show no evidence of teratogenicity.[16]

Both halves of that hold at once. It is not an alarming signal, and it is also nothing like a safety dataset for a months-long cosmetic regimen in a healthy pregnant person, which is a completely different exposure from a single acute obstetric dose.

No study was located assessing topical tranexamic acid specifically in pregnancy.[no source found]

Thrombotic risk factors

The molecule acts on clot breakdown, so thrombotic risk factors and a personal or family history of thrombosis are screening questions before any systemic course. One deep-vein thrombosis was recorded in a 561-patient melasma series, in a patient with familial protein-S deficiency.[5, 12, 13]i A single event does not establish a rate, and it illustrates why that screening sits with a prescriber rather than with a skincare consultation.

Clinical uses and the evidence behind them#

Topical preparations in melasma

One randomised trial of a 2.5% cataplasmin 81 patients found lower end-of-treatment MASI than vehicle: mean difference −11.43 (95% CI −12.49 to −10.37), rated high certainty. That single trial is the estimate the favourable systematic review rests on.[6]

A later route-stratified meta-analysis of 28 randomised trials found topical tranexamic acid not significantly betterthan comparators at 12 weeks (SMD 0.66, 95% CI −0.10 to 1.42, p=0.09), with substantial heterogeneity, and its authors state that data are still required for the topical and intradermal routes.[17] Two systematic reviews of the same literature therefore reach different conclusions, and neither establishes a class effect for tranexamic acid as an ingredient.

Against hydroquinone, no difference in MASI was detectedacross two 12-week trials and 160 patients (MD 0.05, 95% CI −0.29 to 0.38, moderate certainty).[6, 8] That comparison carries particular weight in UK practice, where hydroquinone is prohibited in cosmetic skin-lightening products and prescription-only in medical use.

Against triple combination cream it was inferior: MD −3.34 (95% CI −4.30 to −2.38) in 40 patients.[6] Taken together, the topical evidence describes a middle option rather than the strongest one available.

Oral use in melasma

Short-term oral tranexamic acid improves melasma alongside sunscreen, and as an adjunct to hydroquinone it lowered mean MASI by 1.8 points against hydroquinone alone.[3, 4, 14]

The scope of those trials travels with the result: three months, with sunscreen throughout, in a predominantly Hispanic cohort at a single US centre and a Jakarta cohort respectively. The hydroquinone-adjunct trial was not placebo-controlled — the control arm received hydroquinone with no placebo capsule — and it was assessor- and analyst-blinded rather than double-blind.

Intradermal delivery and microneedling

One 20-person split-face trial found no significant added benefit from tranexamic acid delivered after whole-face microneedling.[9] It is a real negative result, and with twenty participants it cannot exclude a genuine effect either. What it certainly does not do is support needling a retail serum into the face.

Post-inflammatory hyperpigmentation

Tranexamic acid is increasingly marketed for post-inflammatory hyperpigmentation. The prominent report behind that is an uncontrolled practice series of around 82 cases with no controlled outcome data.[15] It is a reasonable prompt for further study, and the melasma evidence does not transfer to every cause of a dark mark.

Selecting a preparation and setting expectations#

The route is settled by law before it is settled by evidence: the oral tablet and the injectable belong to a prescriber, so the decision available inside an aesthetic clinic is which topical preparation, if any.

The positive topical results belong to specific formulations — a 2.5% cataplasm, and 5% gels and solutions, studied mostly in Asian and Indian populations — and one 5% preparation showed no difference from vehicle in a 21-completer Thai trial. A retail serum listing tranexamic acid somewhere in its INCI has not inherited any of that.[6, 7, 8] The formulation and concentration a supplier can point to is therefore the operative question, rather than the presence of the ingredient on a label.

None of the sources reviewed here sets out a regimen for a retail preparation — a concentration, a frequency, or a period after which the result should be judged — so the instructions for the specific product govern. The comparative trials measured their outcomes at twelve weeks.

Expected course and durability

Recurrence after stopping is the defining feature of the oral evidence, and it is where expectations most often break down. Relapse among responders was 27.2% in a 561-patient series. In the randomised adjunct trial, relapse over three months of follow-up was 30% against 26%, a difference that was not statistically significant — while mean MASI at six months remained 1.8 points lowerwith tranexamic acid plus hydroquinone than with hydroquinone alone (95% CI 0.36–3.24, p=0.015).[5, 14]

A non-significant difference in how many people relapsed is not the same as no measurable advantage remaining. Both of those findings concern oral use; recurrence after a topical or intradermal course has not been measured in the sources reviewed here. Control during treatment, rather than clearance, is the expectation the evidence supports.

Adverse effects and their management#

Adverse effects recorded in the topical comparisons

Significantly feweradverse events were recorded with topical tranexamic acid than with hydroquinone (RR 0.16, 95% CI 0.05–0.46).[6, 8] That difference was detected, which makes it the more solid half of that comparison. Beyond the comparative counts, none of the sources reviewed here characterises the adverse effects of topical use in any detail.

The systemic thrombotic signal

A meta-analysis of 22 randomised trials and 49,538 non-surgical patients found no statistically significant increase in venous or arterial thrombosis. Those were bleeding indications, at different doses, for different durations, in different patients.[5, 12, 13]i

A Danish nationwide cohort of women aged 15–49 points the other way. Venous thromboembolism incidence during oral tranexamic acid use was 11.8 per 10,000 person-years(95% CI 4.6–30.2) against 2.5(2.4–2.6) during non-use — an adjusted incidence rate ratio of 4.0(1.8–8.8). Arterial thrombosis was not significantly increased (IRR 1.3, 0.4–4.2).[18]

The absolute scale belongs beside the ratio: the estimated number needed to harm was 78,549 women using it for five days. A fourfold increase on a very small baseline is still a very small number of events. That population was also overwhelmingly taking short courses for heavy menstrual bleeding, most commonly 1 g three times daily for five days, rather than months of low-dose use for melasma.

Reducing, stopping and referring

The topical evidence does not extend past those comparative counts, so no threshold for reducing or stopping a topical preparation can be drawn from it, and the instructions for the specific product govern.

Oral use is settled by remit rather than by evidence: the dose, the duration, the monitoring and any decision to reduce or stop sit with the prescriber, which makes an adverse effect arising on an oral course something to return to them rather than something to adjust in clinic.

Referral and scope boundaries#

A large part of the published melasma evidence sits with a medicine that is not available inside an aesthetic scope of practice, which makes referral a routine part of competent work in this category rather than a limitation of it. Referral is indicated in three situations:

  • A client considering oral tranexamic acid. Prescribing and supply belong to an appropriately qualified prescriber; a non-prescriber refers, and does not sell or supply.[2]
  • A client with thrombotic risk factors, or a personal or family history of thrombosis, who is considering or already taking it. The screening and the monitoring sit with the prescriber.
  • Any request for intradermal administration. The UK injectable is licensed for slow intravenous use only, so intradermal delivery for melasma sits outside its licensed route.[11]

Sunscreen ran throughout the oral trials rather than alongside them, so photoprotection is part of the regimen the evidence describes and continues whether or not a prescriber becomes involved.[3, 4, 14]

Mechanism of action#

Tranexamic acid interferes with the breakdown of blood clots, which is the basis of its licensed use. The proposed pigment effect runs through the plasmin pathway — inflammatory, vascular and melanocyte signalling. The mechanistic detail comes from cultured endothelial cells and melanocytes rather than from patients, so it describes a hypothesis rather than supporting a clinical outcome.[1, 10]i

Commonly misstated claims#

Four statements circulate widely in the trade. Each is set out below with what the primary literature was found to support.

“Topical tranexamic acid is as effective as hydroquinone.”

The systematic review describes the two as equally effective. The trials behind that were not designed as equivalence or non-inferiority studies and no margin was set, so what happened is that a difference was not detected in 160 patients across two 12-week trials.[6, 8]

Supported statement: no difference in MASI was detected between topical tranexamic acid and hydroquinone across 160 patients, and adverse events were significantly fewer with tranexamic acid.

“Tranexamic acid is the strongest topical option for melasma.”

No source reviewed here ranks it first, and the one head-to-head against triple combination cream went against it.[6] Tolerability and potency are separate axes, and only the tolerability finding favours it.

Supported statement: a well-tolerated option rather than the most effective one, outperformed by triple combination cream in the trial evidence reviewed here.

“Oral tranexamic acid is effectively a supplement.”

It is a prescription-only medicine whose licensed indications do not include melasma, which makes its use for pigmentation a prescribing decision rather than a retail one.[1, 2]

Supported statement: a prescription-only medicine used off-label for melasma, prescribed and monitored by a prescriber.

“Tranexamic acid has been shown not to cause clots.”

The two relevant evidence sets differ in design, dose, duration and indication, and neither answers the melasma question. No source reviewed here supports a claim of zero risk, and none provides a melasma-specific rate.[5, 12, 13, 18]i

Supported statement: no increase was detected in bleeding-indication trials, a raised rate ratio at a very small absolute rate was recorded in short-course users, and neither measures months-long use for melasma.

Areas of remaining uncertainty#

  • Whether any topical preparation maintains benefit after it is stopped, or only during use. Until that is measured, control during treatment is the expectation a client can be given.
  • Whether topical tranexamic acid works as a class or only in the preparations that were studied. Two systematic reviews disagree, which leaves the formulation behind the evidence as the practical basis for selection.
  • Rare-event safety of months-long oral regimens in otherwise healthy people. The reassuring meta-analysis studied bleeding indications, which keeps the risk conversation with a prescriber.
  • Whether tranexamic acid does anything useful in post-inflammatory hyperpigmentation. Until a controlled study exists, post-acne marks are outside what can be claimed for it.
  • Whether the negative microneedling result reflects no effect or an underpowered study. Either way, the trial gives no support for delivering a serum through needling.
  • Topical use in pregnancy, where no study was located at all. The absence leaves the decision with the client’s own clinician.

Frequently asked questions#

Can a topical tranexamic acid serum be retailed?

Yes — topical cosmetic formulations sit within an aesthetic practitioner’s scope. The useful question to put to a supplier is which formulation and concentration was studied, because the results belong to specific preparations and one 5% preparation showed no benefit over vehicle.[6, 7, 8]

What can a client be told about oral tranexamic acid?

That it is a prescription medicine used off-label for melasma, that the benefit demonstrated in trials is short-term, that it requires a thrombotic-risk assessment, and that the decision and the monitoring belong to a prescriber.[1, 2]

Does melasma stay away once treatment stops?

Often not. Relapse among responders was 27.2% in one series, and in a randomised trial relapse at three months was not significantly different from control.[5, 14]

Can tranexamic acid be injected or needled into the skin?

The UK injectable product is licensed for slow intravenous use only, which places intradermal delivery for melasma outside its licensed route.[11] The one microneedling-delivery trial found no added benefit.[9]

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. Sovereign Medical. Tranexamic Acid 500 mg Tablets: Summary of Product Characteristics. Electronic Medicines Compendium. Updated 5 May 2026.Tier 1Supports: Product pharmacology, licensed indications, contraindications, thrombotic cautions, pregnancy and lactation information. Melasma is not a listed indication. NOTE: this SmPC does not use the phrase 'synthetic lysine analogue' — do not attribute it here.
  2. Medicines and Healthcare products Regulatory Agency. Off-label or unlicensed use of medicines: prescribers' responsibilities. Drug Safety Update.Tier 1Supports: UK responsibilities for evidence, prescribing, communication, monitoring and follow-up when a medicine is used off-label.
  3. Del Rosario E, Florez-Pollack S, Zapata L Jr, et al. Randomized, placebo-controlled, double-blind study of oral tranexamic acid in the treatment of moderate-to-severe melasma. Journal of the American Academy of Dermatology. 2018;78(2):363–369.Tier 2Supports: Three-month oral regimen plus sunscreen, 44 enrolled and 39 completing, followed three months after stopping. Population was predominantly Hispanic women at a single US centre.
  4. Shihab N, Prihartono J, Tovar-Garza A, et al. Randomised, controlled, double-blind study of combination therapy of oral tranexamic acid and topical hydroquinone in the treatment of melasma. Australasian Journal of Dermatology. 2020;61(3):237–242.Tier 2Supports: Three-month incremental oral effect in 50 completers already using hydroquinone and sunscreen, with three months of post-treatment follow-up. Jakarta cohort.
  5. Lee HC, Thng TGS, Goh CL. Oral tranexamic acid in the treatment of melasma: a retrospective analysis. Journal of the American Academy of Dermatology. 2016;75(2):385–392.Tier 3Supports: Uncontrolled 561-patient Singapore series. Relapse among responders was 27.2%. One deep-vein thrombosis occurred, in a patient with familial protein-S deficiency.
  6. Pennitz A, Kinberger M, Avila Valle G, Passeron T, Nast A, Werner RN. Self-applied topical interventions for melasma: a systematic review and meta-analysis of data from randomized, investigator-blinded clinical trials. British Journal of Dermatology. 2022;187(3):309–317.Tier 1Supports: Concludes: 'Topical TXA proved to be more effective than placebo and equally effective as HQ in treating melasma. However, TXA was inferior to TCC with respect to MASI.' Versus vehicle: MD −11.43 (95% CI −12.49 to −10.37), GRADE HIGH, 81 patients, 2.5% cataplasm. Versus hydroquinone: no significant MASI difference, MD 0.05 (95% CI −0.29 to 0.38), GRADE moderate, 160 patients across two studies — with significantly MORE adverse events on hydroquinone, RR 0.16 (95% CI 0.05–0.46). Versus triple combination cream: TXA inferior, MD −3.34 (95% CI −4.30 to −2.38), 40 patients.Funding / interest: Supported by an unrestricted institutional research grant from Beiersdorf AG; the authors state the sponsor had no influence. T. Passeron disclosed grants and honoraria from Beiersdorf and other companies.
  7. Kanechorn Na Ayuthaya P, Niumphradit N, Manosroi A, Nakakes A. Topical 5% tranexamic acid for the treatment of melasma in Asians: a double-blind randomized controlled clinical trial. Journal of Cosmetic and Laser Therapy. 2012;14(3):150–154.Tier 2Supports: Twelve-week split-face trial in a Thai cohort: 23 enrolled, 21 completed, no significant difference between the studied 5% TXA and vehicle. A single small negative trial, not the weight of the vehicle-controlled evidence.
  8. Janney MS, Subramaniyan R, Dabas R, Lal S, Das NM, Godara SK. A randomized controlled study comparing the efficacy of topical 5% tranexamic acid solution versus 3% hydroquinone cream in melasma. Journal of Cutaneous and Aesthetic Surgery. 2019;12(1):63–67.Tier 2Supports: Twelve-week single-blind comparison in 100 analysed Indian patients. The authors concluded the two were comparable in MASI reduction. Note this is a 5% SOLUTION, not a gel or cataplasm.
  9. Kuster Kaminski Arida D, Rebellato PRO, de Campos GLM, et al. Randomized, double-blind, placebo-controlled split-face trial of the efficacy of tranexamic acid by drug delivery through microneedling in the treatment of melasma. Journal of Cosmetic Dermatology. 2021;20(12):4005–4010.Tier 2Supports: Twenty-person split-face study finding no significant incremental TXA effect after whole-face microneedling. With n=20 this cannot exclude a real effect — an undetected difference is not proof of no difference.
  10. Zhu JW, Ni YJ, Tong XY, et al. Tranexamic acid inhibits angiogenesis and melanogenesis in vitro by targeting VEGF receptors. International Journal of Medical Sciences. 2020;17(7):903–911.In vitroTier 3Supports: Human umbilical-vein endothelial cells and cultured normal human melanocytes. Not a patient outcome or topical absorption study.
  11. Bowmed Ibisqus Limited. Tranexamic Acid 1 g/10 ml solution for injection/infusion (100 mg/ml): Summary of Product Characteristics. Electronic Medicines Compendium. Text revised 28 April 2026.Tier 1Supports: The eMC record is under Bowmed Ibisqus Limited, with Ibigen S.r.l. as marketing-authorisation holder. The injectable is limited to SLOW INTRAVENOUS use — not intradermal delivery for melasma.
  12. Meaidi A, Mørch LS, Torp-Pedersen C, Lidegaard Ø. Oral tranexamic acid and thrombosis risk in women. EClinicalMedicine. 2021;35:100882.Tier 3Supports: Danish cohort of short-course use for heavy menstrual bleeding. Indirect to months-long melasma regimens.
  13. Chornenki NLJ, Um KJ, Mendoza PA, et al. Risk of venous and arterial thrombosis in non-surgical patients receiving systemic tranexamic acid: a systematic review and meta-analysis. Thrombosis Research. 2019;179:81–86.Tier 1Supports: No statistically significant increase in venous or arterial thrombosis across 22 bleeding-indication RCTs and 49,538 patients. Indirect to melasma duration, dose and patient selection — and an absence of a detected increase is not proof of no increase.
  14. Lajevardi V, Ghayoumi A, Abedini R, et al. Comparison of the therapeutic efficacy and safety of combined oral tranexamic acid and topical hydroquinone 4% treatment vs. topical hydroquinone 4% alone in melasma: a parallel-group, assessor- and analyst-blinded, randomized controlled trial with a short-term follow-up. Journal of Cosmetic Dermatology. 2017;16(2):235–242.Tier 2Supports: Adjunctive oral TXA lowered mean MASI by 1.8 points versus hydroquinone alone (P = 0.015). Relapse over three months of follow-up did not differ significantly (30% vs 26%). IMPORTANT: this is NOT placebo-controlled — the control arm received hydroquinone only, with no placebo capsule — and it was assessor- and analyst-blinded rather than double-blind.
  15. Lindgren AL, Austin AH, Welsh KM. The use of tranexamic acid to prevent and treat post-inflammatory hyperpigmentation. Journal of Drugs in Dermatology. 2021;20(3):344–345.Tier 4Supports: A brief practice report of approximately 82 cases with no controlled outcome data. Insufficient for any broad PIH efficacy claim.
  16. UK Teratology Information Service. Use of tranexamic acid in pregnancy. Version 3, June 2022.Tier 4Supports: Pregnancy evidence for systemic TXA is limited: around 230 reported exposed pregnancies, mainly acute late-pregnancy use for medical indications. UKTIS reports no increase in malformations in the available data and no evidence of teratogenicity in animal studies — but this does not establish safety for months-long oral melasma regimens.
  17. Panchal R, et al. Efficacy of tranexamic acid in the treatment of melasma stratified by route of administration: a systematic review and meta-analysis of randomised controlled trials.Tier 1Supports: THE CONTRADICTORY REVIEW. 28 randomised controlled trials, stratified BY ROUTE. Verbatim on the topical route: 'At 12 weeks, topical TXA did not show a significant change with SMD of 0.66, 95% CI -0.10-1.42, P = 0.09 compared to adjuvant treatment' — with substantial heterogeneity, I-squared 92% (P<0.00001). Its conclusion is that 'data are still required for topical and intradermal routes'. Registered because the entry previously carried only the review that favours topical use; two systematic reviews of the same literature disagree, and a page built on claim-level accountability has to say so.
  18. Meaidi A, Morch L, Torp-Pedersen C, Lidegaard O. Oral tranexamic acid and thrombosis risk in women. EClinicalMedicine. 2021;35:100882.Tier 3Supports: THE STRONGEST OBSERVATIONAL SIGNAL IN THIS DOMAIN, and the entry omitted it. Danish nationwide cohort of women aged 15-49. Venous thromboembolism incidence 11.8 per 10,000 person-years (95% CI 4.6 to 30.2) during oral tranexamic acid use versus 2.5 (2.4 to 2.6) during non-use; adjusted incidence rate ratio 4.0 (1.8 to 8.8). Arterial thrombosis was NOT significantly increased: IRR 1.3 (0.4 to 4.2). ABSOLUTE SCALE: the estimated number needed to harm was 78,549 women using oral tranexamic acid for five days to produce one additional VTE. SCOPE: the population was overwhelmingly short courses for heavy menstrual bleeding - most commonly 1 g three times daily for five days - not months of low-dose use for melasma. It is a real signal at a tiny absolute rate, in a different indication and duration.

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