Minoxidil side effects: Disadvantages of using this medication

Hair loss, due to age or certain medical conditions, is one problem that affects both men and women. Be it home remedies or medicated treatments, there seem to be many solutions that people may swear by. While some homemade oil-mixes might do the trick for you, your doctor may also tell you to go for minoxidil, a medication for people with hypertension, which helps with hair loss. It may strengthen your hair follicles, and lead to better density. However, you should also know about minoxidil side effects before making it part of your hair care routine.

What is minoxidil?

It is a vasodilator, a medication that opens up blood vessels, developed to manage high blood pressure (hypertension). A 2007 study, published in The Journal of Clinical Hypertension, showed that it is capable of reducing blood pressure in most people with hypertension. “It works by relaxing blood vessels, and improving blood circulation. However, its unintended side effect — hair growth, led to its widespread use as a treatment for hair loss,” says internal medicine expert Dr Arvind Aggarwal.

It is primarily used in two ways:

• As an oral medication, it is prescribed for severe hypertension, usually when other treatments have failed.
• In its topical form, it is applied directly to the scalp to treat androgenetic alopecia, also known as male and female pattern baldness.

How does minoxidil promote hair growth?

It promotes hair growth through the following ways:

• Vasodilation (increased blood flow): The medication widens blood vessels, enhancing blood circulation to the hair follicles. “This increased oxygen and nutrient supply helps to revive the dormant hair follicles. Better blood flow ensures that follicles receive the essential nutrients required for hair growth,” says cosmetic and aesthetic surgeon Dr Shweta Mishra.
• Prolonged anagen phase (growth phase): Hair grows in cycles, and minoxidil extends the anagen (growth) phase, ensuring thicker and longer hair strands. “This prevents hair from entering the shedding phase too quickly, which ultimately leads to fuller and voluminous hair over time,” says Dr Mishra.
• Reduced hair shedding: Initially, you may experience “shedding,” but this is temporary. “Over time, this medication strengthens the follicles, resulting in less hair fall and better density,” says Dr Mishra.

Usually, at least four months of continuous therapy with minoxidil topical solution is required for hair growth, as per research published in Clinical and Experimental Dermatology in 2022. “For hair loss treatment, men typically use a 5 percent topical solution or foam applied twice daily, while women are often prescribed a 2 percent solution twice daily or a 5 percent foam once daily,” says Dr Aggarwal.

What are the minoxidil side effects?

Is minoxidil safe to use? Here are some of the minoxidil side effects you need to be aware of:

1. Scalp irritation

One of the common minoxidil side effects is mild irritation, redness, or itching following application on the scalp. It can lead to discomfort, and a burning sensation on the scalp, according to research published in StatPearls in 2023. “This may be due to alcohol or propylene glycol in some of the solutions,” says Dr Mishra.

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2. Initial hair shedding

“You may experience increased hair shedding in the initial weeks of using the medication topically,” says Dr Aggarwal. It can be alarming at first, but it is usually a temporary phase before new growth begins. This happens because weaker hair is pushed out, making way for new hair growth.

3. Dryness and flaking of the scalp

The list of minoxidil side effects also includes scalp dryness, and flaking. It may look like you have dandruff. “When you notice these problems, instead of going for a chemical-loaded shampoo, use a gentle, hydrating shampoo to help alleviate this issue,” suggests Dr Mishra.

4. Unwanted facial hair growth

Unwanted facial hair growth is one of the minoxidil side effects. You may notice unwanted hair growth on unintended areas such as the forehead or cheeks. “This can happen if the liquid trickles beyond the scalp while applying it,” says Dr Aggarwal.

5. Dizziness

It is not just topically, but using this medication in oral form may also lead to adverse effects. “You may have mild dizziness, which occurs when the medication is absorbed systemically, though this is more common with the oral form,” says Dr Aggarwal.

6. Swelling in hands or feet

One of the rare minoxidil side effects is swelling in hands or feet. “Having the medication in its oral form can lead to water retention, causing mild swelling in hands or feet,” says Dr Aggarwal. This does not happen while applying the medication.

7. Allergic reactions

Severe itching or rashes are among the rare minoxidil side effects. “Some people may develop hives, severe itching or rashes due to sensitivity to the components in the medication,” says Dr Mishra. If you notice persistent rashes or swelling, stop applying it or consuming it, and reach out to a doctor.

Minoxidil is one of the popular medications for dealing with hair loss. It may help you, but know the minoxidil side effects, including hair shedding, before using it.