FAQ's - Retinoic Acid

Q. What is retinoic acid and why do you add it to the nighttime 5% minoxidil/Xandrox® solutions?  
A. Retinoic acid (tretinoin or all-trans-retinoic acid) has been used for decades as Retin-A® in the treatment of acne. More recently it has been advocated as a treatment for fine wrinkles in the skin.  It works essentially as a chemical peel and as a biologic response modifier. It allows for better penetration of the minoxidil and promotes epithelial cell growth.

Q. Why should I only use it at night? 
A. Retinoic acid is degraded by strong light, so there is no benefit to using it during the day, when the bright light will render the medication ineffective.

Q. Can retinoic acid cause side effects? 
A. It’s not the side effects of retinoic acid that are irritating. It’s the direct effects. Since retinoic acid acts as a chemical peel, it may cause scaling and peeling and redness of the scalp. Chronic use of retinoic acid on the skin will make skin more sensitive to being sunburned. As such, patients should take precautions to wear a hat or use sunscreen even if they use retinoic acid at night and then expose the scalp to long periods of sunlight during the day.

Q. Can I still use minoxidil solutions with retinoic acid, if I like to be out in the sun or get a lot of sun exposure on my job? 
A. Yes, but it would be wise to wear a hat and/or use effective