Minoxidil is a game-changer for hair loss in both men and women. This med has been shown to regrow hair by revitalizing hair follicles and stimulating growth. 1 However, as with any medication, minoxidil may cause some side effects and interactions that you should be aware of before starting treatment.
In this article, we will explore common minoxidil side effects, how long those side effects may last after stopping the medication, potential drug interactions to be aware of, and whether minoxidil is safe for use during pregnancy.
What Are the Side Effects of Minoxidil?
Like any medication, minoxidil comes with the possibility of side effects. It’s important to be aware of these symptoms so you know what to anticipate when you start using it.
Common minoxidil side effects may include:
- Temporary hair shedding: Initially, you may notice your hair shedding more than usual. Don’t be alarmed—this is normal and temporary. Minoxidil works by shortening the resting phase of your hair growth cycle, pushing more follicles into the growth phase. As new hairs start to grow in, older hairs will shed. 2
- Hair growth in unwanted areas: Some people find that minoxidil leads to unwanted hair growth on other parts of their body, such as the face, arms, or legs. This is more likely to occur when the medication is applied excessively, leading to systemic absorption and hair growth in non-treated areas. 3
- Scalp irritation: Minoxidil contains an ingredient called propylene glycol that helps deliver the treatment to your hair follicles. For some, propylene glycol can irritate the scalp. If you experience scalp irritation from minoxidil, consult your doctor about treatment options to relieve discomfort while continuing with your hair regrowth plan. 3
How Long Do Minoxidil Side Effects Last After Stopping?
So, you've decided to stop using minoxidil. What happens next? Here's a breakdown of what to expect as this med clears from your system.
First, the good news is that most of the minoxidil will be out of your body within 4 days of stopping use. This means any itchiness or irritation on the scalp should start improving pretty quickly as the medication dissipates. 1
However, some side effects may linger or emerge after stopping minoxidil. Here's what to keep an eye out for:
- Hair shedding: Minoxidil prolongs the growth phase of your hair cycle. So, when you stop using it, your hair follicles return to their normal cycle lengths again. This means the resting and shedding phases will shorten and lengthen, respectively. Due to this, you can expect hair shedding about 12 to 24 weeks after stopping minoxidil as more hairs re-enter the shedding phase. But don’t panic – this hair loss is temporary.
- Unwanted hair growth: If you had unwanted hair growth in other areas like your face or arms from using minoxidil, this should also start reversing course. Excess facial and arm hair typically resolves in 1 to 3 months. For leg hair, it may take 4 to 5 months to return to normal. This side effect is more common in women, likely because they tend to have more minoxidil-sensitive follicles. 3
The takeaway? While minoxidil leaves your system pretty quickly, it may take a few weeks to months for your hair cycle and growth patterns to get back to baseline.
Minoxidil Drug Interactions
Minoxidil has a few notable drug interactions to be aware of:
- Topical drugs: Minoxidil should not be used with topical treatments like corticosteroids, tretinoin, or dithranol. These topical drugs alter the outer layer of the skin, allowing increased absorption of minoxidil. Research shows this combo can lead to orthostatic hypotension - feeling dizzy or lightheaded when standing up.
- Guanethidine: When used together, minoxidil and guanethidine can cause a dangerous drop in blood pressure. 1
If you are uncertain about whether a med you are taking could interact with minoxidil, it is essential to consult a doctor before starting minoxidil. This can help prevent any unexpected side effects.
Minoxidil Use During Pregnancy
Minoxidil is not recommended during pregnancy or breastfeeding. While there is no definitive proof that minoxidil causes birth defects, some cases of abnormalities have been reported when used during pregnancy. 2
Minoxidil has been associated with a collection of symptoms in newborns called “fetal minoxidil syndrome.” 4 A few published reports describe babies born with:
- Excessive body hair (this gradually disappeared within 6 months)
- Heart defects
- Issues with brain development
- Digestive issues
- Kidney problems
- Limb malformations 4
More research is still needed to determine if minoxidil truly poses risks to a developing fetus. However, due to the potential dangers, it is important to consult a doctor before using minoxidil during pregnancy or breastfeeding.
Conclusion
Minoxidil is generally considered a safe and effective over-the-counter med for treating hair loss. However, as with any drug, some people may experience uncomfortable side effects. Being aware of potential side effects allows you to monitor your symptoms and decide whether the benefits of minoxidil outweigh the risks for you.
It's also important to note that minoxidil is not suitable for everyone. If you are pregnant, breastfeeding, or taking other topical medications, check with your doctor before using minoxidil.
The content in this article is intended for informational purposes only. This website does not provide medical advice. In all circumstances, you should always seek the advice of your physician and/or other qualified health professionals(s) for drug, medical conditions, or treatment advice. The content provided on this website is not a substitute for professional medical advice, diagnosis, or treatment.
