What is Minoxidil?
Minoxidil stimulates the hair follicles, promoting blood flow to the scalp, which prolongs the hair growth phase (anagen phase) and enhances new hair growth.
How does Minoxidil work?
Minoxidil is a vasodilator drug used primarily to treat hair loss and, in some cases, severe arterial hypertension. Its mechanism of action varies according to its use.
- Use for hair growth (alopecia)
- Minoxidil is used in the form of a topical solution or foam to treat androgenic alopecia (male and female pattern baldness). Its performance involves:
- Vasodilation: Increases blood flow in the scalp, which improves the arrival of nutrients and oxygen to the hair follicles.
- Prolongation of the anagen phase: Extends the hair growth phase, preventing premature follicle loss.
- Stimulation of hair follicles: It can reactivate dormant or miniaturized follicles, helping to produce thicker and stronger hair.
- Results:
- It may take 3 to 6 months to show visible effects.
- At the beginning it may increase hair loss (shedding phase), but this is temporary.
- Must be used continuously; if discontinued, hair loss will return.
Indications for Use
Minoxidil is a topical medication used for the treatment of hair loss (androgenetic alopecia) in men and women. Its regular use can help stimulate hair growth and delay hair loss.
How to Use
- Pre-cleaning: Before applying Minoxidil, make sure that the scalp and hair are completely dry.
- Application
- Apply 1 mL of Minoxidil to the affected area of the scalp, using the dropper or spray included in the package.
- Distribute the product with the fingertips to make sure it covers the area well.
- Frequency
- Use twice a day (morning and evening), with an interval of at least 12 hours between applications.
- Absorption time:
- Allow Minoxidil to dry completely before going to bed or combing your hair (at least 2-4 hours).
- Treatment consistency:
- To see optimal results, treatment should be maintained for at least 4-6 months.
Additional Recommendations
- Do not rinse or wash the scalp for at least 4 hours after application.
- Avoid contact with eyes, mouth or irritated skin.
- Wash hands after each application.
- In case of irritation or adverse effects, discontinue use and consult a physician.
Side Effects
These effects are usually mild and localized in the area of application:
- Skin irritation - Redness, itching, dryness or flaking in the area where it is applied.
- Contact dermatitis - May cause an allergic reaction in some people.
- Increased hair loss at the beginning - This is temporary and occurs because the old hair falls out to make way for a new growth cycle.
- Unwanted hair growth - May appear in areas close to the application site (forehead, cheeks, hands) if the product is accidentally spread.
- Burning or stinging sensation - May be felt on the scalp or skin after application.
Important Considerations
- Topical Minoxidil should not be applied to irritated or injured skin.
- Side effects usually disappear upon discontinuation of use, although hair regained may also be lost after discontinuation of treatment.
If you experience worrisome adverse effects, it is best to consult a doctor.
Serious Side Effects
Topical Minoxidil is a common treatment for hair loss, but in rare cases it can cause serious side effects. Although most people experience only mild effects such as scalp irritation or itching, some may experience more serious reactions, such as:
- Severe allergic reactions (anaphylaxis)
- Severe skin rash
- Swelling of the face, tongue or throat
- Difficulty breathing
- Severe dizziness
- Cardiovascular problems
- Palpitations or irregular heartbeat (arrhythmia)
- Chest pain or squeezing sensation
- Shortness of breath
- Hinchazón en extremidades
- Swelling in hands, feet or face, which may indicate fluid retention or cardiovascular problems.
- Dizziness or fainting
- It may be a sign of hypotension (lowering of blood pressure), since minoxidil is a vasodilator.
- Sudden weight gain
- It may be related to fluid retention and overload of the cardiovascular system.
- Redness, burning or severe irritation on the scalp
- It may be an allergic reaction or sensitivity to the product's ingredients.
- Unwanted hair growth (hypertrichosis)
- It may appear on unwanted areas such as the face, arms or back.
What to do if you experience these effects?
- Discontinue use and seek immediate medical attention if there are signs of allergic reaction, cardiovascular problems or severe symptoms.
- Consult a physician before using minoxidil if you have a history of heart disease, hypertension or circulatory problems.
Precautions to reduce risk:
- Use only the recommended dose
- Do not apply on irritated or injured skin.
- Avoid contact with other areas of the body
- Consult a physician if you have a history of heart or blood pressure problems.
Although these adverse effects are uncommon, it is important to use them under medical supervision if there are pre-existing risk factors.
Contraindications and Precautions
Contraindications:
Topical minoxidil should not be used in the following cases:
- Hypersensitivity or allergy to minoxidil or its excipients: May cause severe allergic reactions.
- Scalp irritation or infections: Do not apply on wounds, cuts, eczema, seborrheic dermatitis or infections.
- Use in children under 18 years of age or over 65 years of age: Not recommended due to lack of safety and efficacy studies in these populations.
- People with cardiovascular disease or unstable hypertension: Although it is a topical treatment, it may be absorbed in small amounts and affect blood pressure.
- Pregnancy and lactation: Not recommended for use in pregnant or lactating women due to lack of studies on its effects on the fetus or infants.
- Concomitant use with other topical scalp treatments: May increase systemic absorption and risk of adverse effects.
Precautions:
While topical minoxidil is generally safe for most users, certain precautions should be taken to avoid adverse effects:
- Avoid contact with eyes, mucous membranes and irritated skin: May cause severe irritation. In case of contact, rinse with plenty of water.
- Wash hands thoroughly after application: To avoid accidental transfer to other areas of the body.
- Do not apply more than the recommended amount: Does not increase efficacy and may increase side effects.
- Do not use hair dryer immediately after application: May reduce the absorption of the medication.
- Avoid using alcohol products on the scalp: May increase dryness and irritation.
- Monitoring in people with a history of heart disease: Medical supervision is recommended to avoid systemic effects.
- Discontinue use if serious adverse effects appear: Such as severe irritation, dizziness, swelling in the extremities or unusual palpitations.
Interactions with Other Medications
Topical Minoxidil, used for the treatment of hair loss, generally has low systemic absorption, which significantly reduces the likelihood of drug interactions. However, there are some considerations to keep in mind:
- Antihypertensive Medications
- Although absorption of topical minoxidil is minimal, in rare cases it could potentiate the effect of antihypertensive drugs such as:
- Beta-blockers (e.g. propranolol, metoprolol)
- Diuretics (e.g. furosemide, hydrochlorothiazide)
- Angiotensin-converting enzyme inhibitors (ACE inhibitors) (e.g. enalapril, lisinopril)
- Calcium channel blockers (e.g. amlodipine, nifedipine)
- This could cause an excessive reduction in blood pressure (hypotension), dizziness or fainting.
- Vasodilator Medications
- If the patient is already taking a systemic vasodilator (such as oral minoxidil), the use of topical minoxidil may increase the risk of:
- Hypotension
- Reflex tachycardia
- Dizziness and fatigue
- Recommendation: Do not combine oral minoxidil with topical minoxidil without medical supervision.
- Corticosteroids, Retinoids and Other Topicals
- Concurrent use of topical corticosteroids (e.g. betamethasone, clobetasol) or retinoids (e.g. tretinoin, retinoic acid) on the scalp may:
- Increase systemic absorption of minoxidil.
Irritate the scalp or cause adverse reactions such as dryness, desquamation or dermatitis.
- Recommendation: Avoid applying these products to the same area without consulting a physician.
- Alcohol and Drugs with Vasodilator Properties
- Alcohol in excess can potentiate the hypotensive effects of minoxidil.
- Medications with vasodilator effect (such as niacin in high doses) could increase the risk of dizziness or hypotension.
- PDE-5 Inhibitors (Sildenafil, Tadalafil)
- Medications such as sildenafil (Viagra) or tadalafil (Cialis) have vasodilator effects and could potentiate blood pressure lowering when combined with minoxidil.
Although topical minoxidil has a low risk of interactions, it is recommended:
- Consult your doctor if you are taking antihypertensive or vasodilator drugs.
- Avoid co-use with unsupervised topical corticosteroids or retinoids.
- Monitor symptoms such as dizziness, fainting or palpitations if used with other medications that affect blood pressure.
Conclusion
Topical Minoxidil is a widely used treatment for hair loss, especially in cases of androgenetic alopecia. Its mechanism of action promotes vasodilation and stimulates hair follicles, prolonging the hair growth phase. Although its efficacy varies among individuals, its constant use can help reduce hair loss and promote hair growth.