Tretinoin, also called all-trans retinoic acid, is a prescription retinoid best known for treating acne. In hair loss care, it is sometimes combined with minoxidil in a compounded topical formula. This guide explains why the combination has been studied, what the evidence shows, and the safety points to know.
What each ingredient is
Minoxidil is thought to act on the hair growth cycle and on blood flow around the follicle. Topical minoxidil is FDA-approved for hereditary hair loss. See topical vs oral minoxidil.
Tretinoin (retinoic acid) is a vitamin A derivative that affects how skin cells grow and turn over. It is FDA-approved for acne and some other skin conditions, not for hair loss.
Why they are combined
Minoxidil works only after it is converted into its active form by an enzyme in the scalp called sulfotransferase. People vary in how much of this enzyme they have, which is one proposed reason minoxidil works better for some people than others. Research suggests tretinoin may increase this enzyme's activity and may also help minoxidil penetrate the skin. That is the rationale for combining them.
What the evidence shows
Small studies have reported benefits from combining tretinoin with minoxidil, and some suggest the combination may allow less frequent application. The studies are limited in size and use different formulations. The combination is not FDA-approved, and when prescribed as a single formula, it is compounded by a licensed pharmacy for an individual patient. Compounded medications are not FDA-approved.
Side effects and safety
- Scalp irritation. Tretinoin commonly causes redness, dryness, flaking or stinging, and can make minoxidil irritation more noticeable.
- Sun sensitivity. Retinoids can make skin more sensitive to sunlight, so protect your scalp from the sun.
- Absorption. Because tretinoin can increase how much minoxidil passes through the skin, a provider needs to review your history, including any heart or blood pressure conditions.
- Pregnancy. Retinoids are generally avoided during pregnancy, and minoxidil is generally not recommended during pregnancy or breastfeeding. Tell your provider if you are pregnant, planning pregnancy or breastfeeding.
Use only as prescribed, and report side effects to your provider.
Who might consider it
A provider may consider this combination based on your hair loss pattern, history and how you have responded to other treatments. Whether it is appropriate for you is a clinical decision. Hair changes slowly, so providers typically evaluate response over months rather than weeks.
Next step
If you want a licensed provider to review your options, start your online consultation.
Prescription required. A licensed provider decides whether treatment is appropriate. Compounded medications are prepared by a licensed pharmacy for an individual patient and are not FDA-approved. Individual results vary. Prescribed Essence currently serves patients in California, Colorado, Florida and New York.
