# Tranexamic acid vs kojic acid Source: https://theconstantbeauty.com/compare/tranexamic-acid-vs-kojic-acid/ Retrieved for: theconstantbeauty.com Publisher: The Constant (theconstantbeauty.com). Cite as "The Constant". Generated: 2026-09-16T18:18Z **Compares:** Tranexamic acid vs Kojic acid **Criteria:** What it is, Where it acts, Typical cosmetic use level, Stability in formula, Tolerability, Regulatory status (to our understanding), Evidence base ## Context for the verdict Choose tranexamic acid if your uneven tone flares after sun exposure or after irritation, if your skin is sensitive, or if you want an ingredient that layers easily with niacinamide, vitamin C derivatives and gentle acids. It is the lower-drama option and the one with the better stability record. Choose kojic acid if you want a direct tyrosinase inhibitor, you tolerate it well on a patch test, and you are buying a product in airless, opaque packaging that you will finish within a few months. Stay at or below 1%, and stop if you notice redness, itching or a rash. Neither works quickly. Plan on 8–12 weeks of daily use alongside sunscreen before judging either one, and expect the sunscreen to do at least half the work. ## Comparison Both ingredients are used for a more even-looking tone, but they act at different points in the pigment pathway and behave very differently in a formula. Tranexamic acid is a synthetic derivative of the amino acid lysine. In skin it reduces plasmin activity in surface cells after UV exposure or irritation. Plasmin is one of the signals that tells pigment cells to increase output, so damping it lowers the trigger rather than blocking the enzyme. It is water-soluble, stable across normal formulation pH, colourless, and has a good tolerability record in the topical studies published so far, which typically use 2–5% over 8–12 weeks. Occasional dryness or mild irritation is the most common complaint. In Japan it is an approved quasi-drug active for tone concerns. Kojic acid is produced by fermentation, historically by the moulds used to make sake and soy sauce. It inhibits tyrosinase, the copper-dependent enzyme that produces pigment, by binding the copper at its active site. That direct action is why it has a long history in tone products. Its weaknesses are practical: it oxidises readily and browns in the bottle, it is light-sensitive, and it is a recognised contact sensitiser, with irritation and allergic reactions reported more often as concentration and duration increase. Kojic dipalmitate, a more stable ester, is often used instead, though whether it converts back to kojic acid in skin is not well established. Regulation reflects that record. The EU’s Scientific Committee on Consumer Safety concluded that 1% kojic acid in face and hand creams is safe, and, to our understanding, a 2024 amendment to the Cosmetics Regulation added a 1% limit to Annex III. We are not aware of a specific concentration limit for either ingredient in India, where both are used in cosmetics, and tranexamic acid is not restricted in the EU annexes as far as we know. Rules change; check the current text before relying on this. ## References 1. Maeda K, Naganuma M. Topical trans-4-aminomethylcyclohexanecarboxylic acid prevents ultraviolet radiation-induced pigmentation. J Photochem Photobiol B. 1998;47(2–3):136–141. 2. Scientific Committee on Consumer Safety (SCCS). Opinion on kojic acid. SCCS/1481/12, 2012. 3. Saeedi M, Eslamifar M, Khezri K. Kojic acid applications in cosmetic and pharmaceutical preparations. Biomed Pharmacother. 2019;110:582–593. 4. PubChem compound summaries: tranexamic acid (CID 5526), kojic acid (CID 3840). National Library of Medicine.