Tranexamic Acid for Melasma: What the Studies Show

Tranexamic acid (TXA) comes from a very different field of medicine. It is an antifibrinolytic, a drug usually used to help stop bleeding. Dermatologists have also studied it for melasma, with published trials dating back to at least 2006.

Interest is high, and so is the amount of confusing information online. This article sets out what dermatology references and published reviews actually report, including the limits of that evidence.

TXA tablets are a prescription medicine. If you are considering any form of TXA, talk to a dermatologist about whether it suits you.

How tranexamic acid is thought to work

DermNet notes that the way TXA works in melasma is not fully understood. Proposed effects include:

• Shrinking small blood vessels in the dermis
• Changing signals between skin cells (keratinocytes) and pigment cells (melanocytes), which reduces melanin production
• Lowering the activity of tyrosinase, a key enzyme in melanin production

DermNet’s melasma page links this to TXA’s effect on the conversion of plasminogen to plasmin and on related downstream factors.

Ways it is used

Researchers have studied three routes.

The AAD describes TXA as an option when other treatments have not worked, applied to the skin or taken as a pill twice a day. It asks patients to tell their dermatologist if they have ever had a blood clot.

DermNet notes that dermatology use is off-label: the drug is not licensed for skin conditions.

What the meta-analyses found

A 2018 systematic review

A 2018 systematic review and meta-analysis in BioMed Research International pooled 21 studies with 1,563 patients, most of them women. It included 16 randomized controlled trials.

Key findings:

• TXA on its own was linked to a significant drop in the Melasma Area and Severity Index (MASI), a standard severity score.
• Oral, topical and injected TXA each showed a significant reduction.
• Used alongside routine treatment, oral TXA added a further benefit. Topical TXA as an add-on did not reach significance, but only one study tested it.
• Side effects were described as minor.

The authors called TXA effective and safe. They also said the evidence was not strong enough for a firm conclusion, because study quality was generally low and doses, follow-up times and scoring methods varied.

A 2023 meta-analysis of randomized trials

A meta-analysis in the Indian Dermatology Online Journal looked at 28 randomized trials. Thirteen tested oral TXA, nine topical and seven intradermal.

Compared with standard treatment:

• Oral TXA showed significant improvement at both 8 and 12 weeks.
• Topical TXA showed no significant difference at either time point.
• Intradermal TXA also showed no significant difference.

The authors concluded that oral TXA can be used alone or with other standard treatments. Variation between the included studies was very high, which limits how firmly these results can be read. This review did not assess side effects or differences by skin color.

A 2019 review of formulations

A short review in the Journal of Clinical and Aesthetic Dermatology reached a similar view. It found that oral TXA showed the most promise, but with temporary benefit.

Two placebo-controlled trials it described:

• One reported 49% MASI improvement with oral TXA after three months, versus 18% with placebo.
• Another reported about 50% improvement at 12 weeks, versus 5.9% with placebo.

For topical TXA, most small studies showed improvement from baseline, but results generally did not differ significantly from the inactive cream (vehicle). Evidence for injections was limited and mostly lacked control groups.

Side effects reported

Most published data come from relatively small studies. DermNet draws on a case series of 561 patients treated for a median of about four months, in which 7% reported an adverse event.

Reported effects with oral TXA include:

• Stomach upset, heartburn and nausea
• Headache
• Menstrual changes, including less frequent periods
• Numbness or tingling in the face or fingers
• Rare allergic reactions such as rash with swelling

Topical TXA has been linked to skin irritation, dryness and scaling. Injections can cause temporary swelling and pain at the injection site.

Clotting risk and who should be cautious

Because TXA affects blood clotting, the main safety question is thrombosis. In the 561-patient series, one person developed a deep vein thrombosis and was found to have an underlying clotting disorder.

The 2019 review notes that serious events such as deep vein thrombosis and pulmonary embolism were rare, likely because melasma doses are low. Its authors still suggest screening for clotting risk.

DermNet lists situations where TXA should not be used, including:

• A personal or family history of clotting disorders
• Previous venous thromboembolism
• Ischemic heart disease or stroke
• Severe kidney problems
• A history of seizures

DermNet states that thrombotic risk cannot be entirely excluded. Long-term safety, especially in older patients, is largely unknown. These are reasons the decision belongs with a prescriber who knows your medical history.

Relapse after stopping

TXA does not appear to offer a permanent fix. In one uncontrolled study described in the 2019 review, MASI improved by 69%, yet 72% of patients relapsed within two months of stopping. DermNet also notes that melasma may recur after treatment ends, and BAD says melasma often returns after stopping treatments in general.

How to maintain results after TXA is still an open research question.

Where TXA fits in a wider plan

Dermatology sources describe melasma care as a combination approach. DermNet lists lifelong sun protection, avoiding hormonal triggers where possible, topical treatments and, in selected cases, procedures. TXA is one possible part of that plan, and sun protection remains the base layer.

The AAD notes that melasma results usually take 3 to 12 months, and longer for long-standing melasma.

Points to raise with a dermatologist

• Is my melasma type likely to respond to TXA?
• Do my medical or family history, or my current medicines, raise clotting concerns?
• Which route, if any, has the best evidence for my situation?
• What is the plan for maintaining results if I stop?

The bottom line on the evidence

Across reviews, oral TXA has the strongest evidence of the three routes, though trials vary widely in quality and design. Topical and injected forms have weaker support. Relapse after stopping is common, and clotting risk requires individual assessment. Larger, well-designed trials are still needed, as the review authors themselves point out.