Oral minoxidil side effects and what's normal

The side effect people notice most on oral minoxidil is unwanted hair growth on the face or body. Minoxidil tablets also carry a boxed warning, so it is worth reading this before you start and knowing which signs need care right away.

Most common: unwanted hair growth

Longer, thicker or darker hair where you do not want it, on the face, arms, back or legs. It is usually noticed within 3 to 6 weeks of starting, is reported more often by women than by men, and is more likely at higher doses.

It is generally reversible: it usually slows and reverses within 1 to 6 months of stopping. If it happens, tell your provider rather than changing your dose yourself. They can lower your dose or talk through other options with you.

Other common side effects

• Salt and water retention, and swelling in the ankles, legs or face
• Lightheadedness, dizziness or low blood pressure, especially when standing up
• A faster heartbeat
• Headache, which often eases over time
• Breast tenderness
• Nausea or vomiting
• Changes on an ECG (a heart tracing)

This is not a complete list. Contact us if any side effect keeps going, gets worse, or concerns you.

Early shedding is expected

Some people shed more in the first weeks. That is resting hairs being released to make room for new growth, not a sign that something is wrong, and it usually settles within about a month. Tell us if it continues.

The boxed warning

Minoxidil tablets are FDA-approved to treat high blood pressure, and they carry a boxed warning (the FDA's strongest label warning) for serious heart-related effects. Minoxidil can cause fluid to build up in the sac around the heart (pericardial effusion), which can occasionally press on the heart and stop it beating normally (tamponade). It can also make angina (chest pain) worse.

The warning comes from the much higher doses used for blood pressure, but it still applies at hair-loss doses. Do not change your dose without talking to your provider.

Get emergency care right away (call 911) for

• Sharp chest pain, or pain spreading to your arm or shoulder
• New chest pain, or chest pain that comes on more often or more easily than before
• Shortness of breath
• Fainting, severe dizziness, or confusion
• Swelling of the face, lips, tongue or throat, or a rash that blisters or peels

Contact your provider promptly if

• Your resting pulse is 20 or more beats per minute above your usual
• You gain 5 pounds or more quickly, or notice new swelling or puffiness in your face, hands, ankles or belly
• You feel lightheaded or dizzy often, especially when you stand up
• A side effect keeps going, gets worse, or worries you

Your provider may ask you to weigh yourself regularly and check your resting pulse, especially when you start or change your dose.

Pregnancy and breastfeeding

Belle does not prescribe oral minoxidil if you are pregnant, trying to become pregnant, or breastfeeding. Minoxidil passes into breast milk. Tell your provider right away if you become pregnant while taking it.

Full safety information

Read Belle's full Important Safety Information for oral minoxidil at joinbelle.com/important-safety-information/oral-minoxidil. To report a side effect to the FDA, call 1-800-FDA-1088 or visit fda.gov/medwatch.

Have a question? Reach out to our care team. They're here to help.