Important Facts to Know About Minoxidil for Hair Loss

Whether you’ve experienced hair loss or not, you’ve probably heard of minoxidil, aka Rogaine. Applied to the scalp, it can be a helpful aid to stimulate hair growth for both men and women with a certain type of hair loss. Though it is available over-the-counter, it’s best to consult with a dermatologist, plastic surgeon and/or hair-loss expert to find the right product and usage to suit your needs. Minoxidil may seem straightforward, but both the topical and oral versions of the medication come with risks. Here, three things you probably haven’t heard about the drug that you should know.

Featured Experts

• Doris Day, MD, a board-certified dermatologist based in New York
• Dr. Aleksandra Brown, a board-certified dermatologist based in Blacksburg, VA
• Samantha Ellis, a board-certified dermatologist based in Danville, CA

Oral Minoxidil Can Cause Hair Growth in Other Places

“If you’re trying to grow hair only on your head, don’t take oral minoxidil,” says Dr. Day. “Minoxidil is not specific to growing hair only on the scalp. It will work where you use it. If you take it by mouth, it’s going to work systemically. So, if it’s growing hair on your head, it’s also growing hair anywhere that you tend to grow hair.” Also, Dr. Day points out that studies show that whether minoxidil is taken orally or applied topically, “the results are the same.” Talk to your doctor about the risks and benefits of each to find the best solution for you.

Minoxidil for Hair Loss Might Not Work for You for a Few Different Reasons

If you’ve been using minoxidil for several months and you’re not seeing any improvement in your hair growth, there may be a reason outside your control. “Your hair loss may be caused by something other than androgenetic alopecia,” says Dr. Brown. “Minoxodil is FDA-approved to treat androgenetic alopecia, which is genetically inherited hair loss and thinning. It might not be as effective on hair loss caused by medication.” Another reason it may not be working for you is that you may not have the right enzyme. “Your hair follicles might not have the enzyme that is needed to activate minoxidil. This enzyme is called sulfotransferase [SULT1A1] and it’s present in your liver.” You also have to be consistent with minoxidil, and if you’re not, it won’t perform. “It requires daily use and you have to stick with it for at least three to six months,” adds Dr. Brown.

Topical Minoxidil Can Be Toxic to Pets

“Topical minoxidil for treating hair loss can absolutely [kill] your cat or dog,” says Dr. Ellis. “As a dermatologist who specializes in hair loss, this is something I discuss with all of my hair-loss patients. Although topical minoxidil is an excellent treatment, it is not worth the life of your pet. And unfortunately, it’s very small amounts that can fatally toxic, like your cat linking your fingertips or your forehead where you’ve applied minoxidil. Or, laying on your pillowcase that you slept on all night. Based on some data from the Animal Poison Control Center database, it seems like the most common exposures are from cats licking small drops of minoxidil and dogs rummaging through their owner’s trash and coming in contact with a minoxidil container. For most of my patients who are cat or dog owners, the risks of having topical minoxidil in their homes, simply aren’t worth it. And in those cases, we can shift the discussion to the benefits of oral minoxidil or other hair-loss interventions.”