Topical Minoxidil
Topical minoxidil is one of the primary ways to treat hair loss. This FDA-approved and UK-licensed medication is available in two easy-to-use forms: a solution and a foam. Users simply apply the minoxidil topical solution to areas of the scalp with thinning hair.
Minoxidil’s success depends on activation by the sulfotransferase enzyme, which is abundant in the liver but varies significantly between individuals’ hair follicles. By utilizing the liver’s consistent enzyme supply, oral minoxidil often proves more effective for patients who lack the follicular chemistry required to benefit from topical applications.
Minoxidil Side Effects
Being aware of side effects can help you manage treatment safely and effectively. Always read the patient information leaflet for full instructions and precautions.
While both forms are effective, their delivery methods lead to different potential side effects. Topical minoxidil primarily causes localized reactions, whereas oral minoxidil may have systemic effects due to its absorption into the bloodstream.
However, first, we look at the known side effects of both oral and topical minoxidil.
Common Minoxidil Side Effects
- Unwanted hair growth (hypertrichosis) in other areas, especially with stronger doses.
- Temporary hair shedding: Expect increased shedding during the first 6 weeks, called “dread shed.” This happens as minoxidil pushes follicles into the growth phase (anagen). It typically stops within a month.
Learn about side effects for each formulation and for men versus women.
Brief oral and topical minoxidil side effect comparison:
| Feature | Topical minoxidil (foam/liquid) | Oral minoxidil (low-dose Pill) |
| Effect area | Only on the scalp | Whole body |
| Skin | Itching readiness dry scalp | None |
| Extra hair | Rare (if it drips on the face) | Common (face/body) |
| Heart/blood pressure (BP) | Very rare | May cause dizziness, fast heart, or low BP |
| Swelling | Very unlikely | May cause ankle, foot or eye swelling |
Oral Minoxidil Side Effects
As this is an off-label use of a blood pressure medication, it’s usually prescribed at very low doses (typically 0.625–5 mg) to help minimise potential side effects.
However, select patients experience the following side effects from the oral formulation:
- Postural hypotension: Dizziness when standing from a sitting or lying position
- Tachycardia: A fast-paced heartbeat that exceeds 100 beats per minute.
- Lower limb oedema: Fluid retention that causes weight gain or lower leg, feet and ankle swelling.
Uncommon Side Effects
In sporadic cases, men and women have experienced the following symptoms:
- Breast tenderness
- Chest pain
- Heart failure
- Insomnia
- Nausea
- Nightmares
- Pericarditis
- Skin rash
- Vomiting
- Weight gain
Topical Minoxidil Side Effects
Most side effects are usually linked to the liquid’s carrier ingredients (such as propylene glycol), rather than the medication itself.
Possible scalp reactions can include:
- Dryness and dandruff from alcohol-based solution
- Contact dermatitis and itching
- Skin redness (erythema)
- Facial hair growth. It usually resolves 1-3 months after stopping treatment)
Note: Some people find the foam formulation less irritating than the solution, as it doesn’t contain propylene glycol.
Disclaimer: This content is meant for informational purposes and is not a substitute for professional medical advice.
Minoxidil Side Effects in Women
According to a 2019 review, unwanted hair growth is more common in women using 5% topical minoxidil, though the reason is unclear. Some women may have hair follicles that respond more strongly to the medication.
Pregnancy & Breastfeeding
Minoxidil is not recommended during pregnancy or breastfeeding due to potential risks.
Disclaimer: This content is meant for informational purposes only and is not a substitute for professional medical advice. You should consult with a registered specialist before beginning any new treatment plan.
Frequently Asked Questions
Disclaimer: This content is meant for informational purposes and is not a substitute for professional medical advice.
Can I use both topical and oral minoxidil?
It’s usually not recommended to use both topical and oral minoxidil together. In some cases, a doctor may supervise the use of both, but only under medical guidance.
One recent study examined patients who started using oral minoxidil while still using topical minoxidil. Researchers found that overlapping treatments could temporarily increase hair shedding if not carefully managed. This shows why doctor supervision is essential.
Who cannot use minoxidil?
Both forms of minoxidil have various potential side effects and, depending on the patient, can be unsuitable for use.
Minoxidil can be especially unsafe for patients with:
- A history of heart problems, such as heart disease or failure
- Existing hepatic (kidney-related) or renal (liver-related) conditions
- Very low blood pressure
- Pheochromocytoma (an adrenal gland tumour)
It is essential to consult with a doctor to determine a treatment plan that takes all factors into consideration. Ensure you disclose all your health conditions, allergies, and current medications during your initial medical consultation.
What alternative medications are there to minoxidil?
There are two other drugs predominantly used to treat male pattern baldness and hair loss — finasteride and dutasteride.
Originally developed to combat benign prostatic hyperplasia (an enlarged prostate), these medicines work by preventing the conversion of testosterone into dihydrotestosterone (DHT) — a male hormone that shrinks hair follicles and prevents hair growth.
Can minoxidil topical be used on other parts of the body?
No, unless directed by your physician. Although it can sometimes cause hypertrichosis on the body or face, minoxidil topical solution for hair loss should only be used on the scalp in the exact amount prescribed by your doctor.
Using a higher concentration of minoxidil foam or cream, using it too often, or using it on other parts of the body increases the risk of absorption through the skin and unwanted effects on your heart and blood vessels.
Research on minoxidil for beard growth is limited, so it’s hard to draw clear conclusions. A 2016 study found that applying liquid minoxidil twice daily for 16 weeks led to noticeably thicker beard growth compared with a placebo.
There are no dedicated studies into the efficacy of using minoxidil for body hair growth.
How long does minoxidil take to work?
For some, minoxidil hair regrowth results have appeared as early as eight weeks with regular dosing.
However, others might have to wait a few months — up to 16 weeks — before they start seeing results.
What should I do if I accidentally miss a dose of minoxidil?
If you miss a dose of minoxidil, simply skip the missed dose and resume your regular schedule. Do not apply a double amount or take an extra pill to “make up” for the lost dose. Doubling up will not speed up hair growth; instead, it significantly increases your risk of side effects like scalp irritation, lightheadedness, or unwanted body hair.
