Route · Injection

Tranexamic acid injection: there is no vehicle control — only a trial comparing two routes

In a 27-person split-face trial, microinjection and mesoneedling did not differ in mMASI change (SMD −0.39, 95% CI −0.93 to 0.15, p = 0.157). Yet satisfaction was significantly higher for mesoneedling (p = 0.007) — and erythema, scaling and oedema were significantly higher on that same side (p < 0.001). No trial with the drug removed is on this page.

Last checked Sep 21, 2026

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What it is: Delivering tranexamic acid into the skin directly. Used for melasma.
What it is used for: Either injected repeatedly with a fine needle (microinjection) or pushed in shallowly with a multi-needle device (mesoneedling).
How it is said to work: Tranexamic acid is said to damp the signalling that drives pigment production. Same substance as the applied and swallowed routes — only the route differs.

There are no numbers and no citations in this box. What has been established, and how far, is below.

At a glance

Session length: 15–30 min
Pain: Moderate
Downtime: 1–3 daysReported in a trial
Sessions: 3 sessionsReported in a trialThe trial above ran at weeks 0, 4 and 8.
How long it lasts: 1 monthsReported in a trialThe trial above read only to four weeks after the last session. Beyond that is unverified, and melasma returns if the sun is not kept off it.
Relative cost: Lower
How well established: Not established

“Reported in a trial” means a number a study on this page actually reported. “Typical range” is not a measured value but roughly how it is usually done, and it varies by clinic and by person.

Cost is not an amount but a band: where this procedure falls when the ones on this site are lined up per session, or per area treated. Real prices differ several-fold by clinic and by how much is treated, so they are not given here. Surgery is measured on a different scale and cannot be compared with this band.

This is not how large the effect is but how well confirmed it is. It shows the highest grade among the findings on this page.

Korean classification Being checkedThe regulatory class has not yet been confirmed against a primary document. It will be filled in once it is.

Tranexamic acid is used for melasma, and this site has a page for the applied route. This page is about putting it into the skin directly.

We start with this page's limit: there is no vehicle-controlled trial.

What we found compares two ways of delivering tranexamic acid — microinjection with a fine needle, and mesoneedling, pushed in shallowly with a multi-needle device. The same drug goes into both sides.

That design cannot say whether putting tranexamic acid in does anything for melasma at all. The problem set out on the PRP page repeats here intact.

But something inside this trial is worth reading. The blinded assessor's scores did not differ, yet satisfaction was significantly higher on one side — the same side that had significantly more adverse effects.

This site does not deal in prices, clinics or reviews.

What is established

Not established

On the blinded assessor's score, the two routes did not differ

A 2023 trial at Isfahan University in Iran. Randomised, assessor-blind, split-face.

People with symmetric facial melasma took part: all 27 were women, mean age 44.22 ± 8.39.

One side of the face — tranexamic acid 100 mg/ml by mesoneedling
The other side — tranexamic acid by intradermal microinjection

Treatments ran at weeks 0, 4 and 8, with the primary outcome read four weeks after the last session. That outcome was improvement in mMASI (modified Melasma Area and Severity Index).

Results:

mMASI scores before and after were comparable between the two
the change from baseline did not differ either — SMD −0.39 (95% CI −0.93 to 0.15, p = 0.157)

How to read it.

First, this compared two sides of the same face. Age, skin and habits cancel out automatically, so a large difference between the routes would likely have shown.

Second, 'no difference' is still not 'the same'. Failing to find a difference between two routes in 27 people can mean there is none, or that there was not the power to find one. The interval runs from −0.93 to 0.15 — it crosses zero.

Third, and most importantly: nothing here had the drug removed. Tranexamic acid went into both sides. So this trial says 'the two routes are similar' and does not say 'putting tranexamic acid in lightens melasma'.

Melasma rises and falls on its own with the season and with sun exposure. People in a trial generally take more care with sun than usual. With no control, that is counted as the procedure's work.

Hence 'not established'.

Randomised controlled trial in people · 27 participants · 12 weeks · Compared with another active ingredient · Funding not declared · Endpoint scores from blinded assessors PMID 36606390

Not established

Yet satisfaction was higher on the side with more adverse effects

Same trial, same 27 people, same faces.

The secondary outcomes were complications and satisfaction on a visual analogue scale.

Satisfaction — significantly higher for mesoneedling (SMD 0.77, 95% CI 0.21 to 1.32, p = 0.007)
Erythema, scaling and oedema — significantly higher with mesoneedling (p < 0.001)
Post-inflammatory hyperpigmentation occurred in one patient in the mesoneedling group

Put those two lines side by side.

The blinded assessor's mMASI was the same on both sides. Yet the participants preferred one side, and it was the side that went redder, flakier and more swollen.

We have met this mismatch repeatedly on this site. On PRP, participants found a difference masked dermatologists did not; GHK-Cu was the same. On minoxidil, 2% split the other way.

But there is something here the others did not have: the side with the bigger reaction was rated better.

We will not say which reading is right. We will set out the two available.

Mesoneedling may really be better, and 27 people may not have been enough to catch that on mMASI.
Or going red and peeling may have read as 'something is happening'. The design let participants tell the sides apart.

The paper's own conclusion carries the same tension — the two were comparable and satisfaction favoured mesoneedling, but it says the high frequency of complications on that side should be taken into account.

We record it as a result that makes you think again about what satisfaction with a cosmetic procedure is made of.

Randomised controlled trial in people · 27 participants · 12 weeks · Compared with another active ingredient · Funding not declared · Endpoint self-reported improvement PMID 36606390

Known risks

In the trial above, erythema, scaling and oedema were significantly more frequent with mesoneedling (p < 0.001).
Post-inflammatory hyperpigmentation occurred in one person. A procedure aimed at pigment can leave pigment behind, so we write it down explicitly.
Needles go in. The risks of infection and bruising remain.
Tranexamic acid acts on clotting. If you have a history of thrombosis or take related medicines, check in a consultation first. The trial above did not address that.
Melasma returns if the sun is not kept off it. See why sunscreen carries 'strong evidence' on this site.
This is a clinical procedure.

What is not established

We could not include a trial with the drug removed. This is the largest hole on the page.
27 people, one trial.
It was read only to four weeks after the last session. What happens later is unverified.
No trial comparing it with the applied or swallowed routes is on this page. See the applied tranexamic acid page alongside it.
How many sessions is right — we found no settled data.
We have not yet opened the primary Korean regulatory classification, so it stays 'being verified'.

Whether to have it done is a decision to make with a doctor.

What this article relies on

PubMed — 미국 국립의학도서관 문헌 데이터베이스National Library of Medicine · Checked on 2026-09-16