Intradermal tranexamic acid and melasma: a systematic review and level of evidence

BACKGROUND: Melasma is a common acquired pigmentary disorder characterized by symmetrical hyperpigmentation, mainly affecting sun-exposed areas of the face and neck. While not medically severe, melasma significantly impacts the quality of life due to cosmetic and psychological concerns. This systematic review evaluates the efficacy and safety of intradermal tranexamic acid (ID TXA) at varying dosages for melasma treatment, comparing it with established therapies such as hydroquinone (HQ), laser treatments, and oral TXA. METHODS: A search of the literature was performed using the electronic databases PubMed and Ovid by selecting the words “Melasma and mesotherapy, “Melasma and intradermal” and “Melasma and injection.” RESULTS: The study examined ID TXA concentrations of 4 mg/mL, 100 mg/mL, and other variations. TXA 4 mg/mL showed significant improvement in melasma severity, often comparable to or better than alternative treatments like HQ 4% or laser therapy, albeit with mild and transient side effects. TXA 100 mg/mL demonstrated similar or superior efficacy to HQ and oral TXA, with a lower recurrence rate than laser therapy. CONCLUSIONS: Overall, ID TXA is a well-tolerated and effective treatment for melasma, with varying concentrations offering different efficacy and safety profiles.