Valerie George01.01.24
—Lighten Up
Dear Lighten:
The acid in tranexamic acid is a bit of a misnomer since it’s not an acid in the way we think of acids in skin care. Meaning, it doesn’t have the desquamation properties of alpha hydroxy or beta hydroxy acids. It doesn’t require an acidic pH to be active. Also, it is efficacious on all skin tones without some of the negative effects associated with other skin brighteners.
Tranexamic acid is an analogue of an amino acid, lysine, and it’s purported to have antiplasmin activity, which helps prevent UV-induced pigmentation. While the concise mechanism of tranexamic acid is unknown, it’s thought that it decreases tyrosinase activity in melanocytes by preventing the binding of plasminogen to keratinocytes. This results in a reduction in prostaglandins and arachidonic acid, two inflammatory molecules associated in the production of melanin pigment. Stop plasminogen, and you stop pigment production.
Tranexamic acid is water soluble and easy to formulate with; simply add it to your formulation like sugar to water. Most suppliers recommend 0.1-3% use levels for tranexamic acid, and the studies in peer-reviewed literature commonly range from 1-3%. It’s stable to light, temperature, pH and oxygen, and there are relatively no special protections needed in the formulation aside.
Skin brightening requires multiple modalities—not only preventing new pigment from forming but removing existing pigment. Since its activity is not pH dependent, I recommend formulating your final product to have a pH of 6-7 and couple it with another skin brightener, like niacinamide.
Valerie George
askvalerie@icloud.com
Valerie George is a cosmetic chemist, science communicator, educator, leader, and avid proponent of transparency in the beauty industry. She works on the latest research in hair color and hair care at her company, Simply Formulas, and is the co-host of The Beauty Brains podcast. You can find her on Instagram at @cosmetic_chemist or showcasing her favorite ingredients to small brands and home formulators at simply-ingredients.com