What is the recommended protocol for using minoxidil (2% or 5% solution) for treating hair loss?

From the FDA Drug Label

Apply minoxidil topical solution 5% once in the morning and once at night. The nighttime application should occur 2 to 4 hours before going to bed to allow for drying. For best results, apply 1 mL with applicator 2 times a day directly onto the scalp in the hair loss area. Using more or using more often will not improve results. Each bottle should last one month, if used as directed

The recommended protocol for using minoxidil (2% or 5% solution) for treating hair loss is to apply it twice a day, once in the morning and once at night, with the nighttime application occurring 2 to 4 hours before bedtime. The application should be 1 mL directly onto the scalp in the hair loss area. It's essential to note that:

• Using more than the recommended amount or applying more often will not improve results and may increase the risk of side effects.
• Each bottle should last one month if used as directed.
• It's crucial to allow the solution to dry completely before wearing a hat, lying on a pillow, or going to bed.
• Mild shampoo should be used if the scalp is washed before applying minoxidil topical solution 5%.
• Hair sprays, mousses, conditioners, and gels can be used on the hair while using minoxidil topical solution 5%, but it's recommended to apply minoxidil first and then styling products. 1, 1, 1

From the Research

The recommended protocol for using minoxidil for treating hair loss involves applying the 5% solution twice daily to a dry scalp, as it has been shown to be more effective than the 2% formulation in promoting hair growth and reducing hair loss 2.

Key Considerations

• For men, the 5% solution is typically recommended, while women may start with the 2% solution to minimize side effects, though many women also use the 5% version.
• Apply 1 mL of the solution to the affected areas of the scalp using the provided dropper or spray applicator, gently massaging it in and allowing it to dry completely before styling hair.
• Consistency is crucial - minoxidil must be used continuously twice daily for at least 4-6 months before noticeable results appear, and treatment should be maintained indefinitely as hair loss will resume if usage stops.

Mechanism of Action and Side Effects

• Minoxidil works by prolonging the growth phase of hair follicles and increasing blood flow to the scalp, which helps revitalize shrunken follicles.
• Common side effects may include initial shedding in the first few weeks (a positive sign the medication is working), scalp irritation, or unwanted hair growth elsewhere if the solution drips onto other skin areas.
• If severe irritation occurs, reducing to once-daily application or switching to the foam formulation, which contains less propylene glycol, may help minimize these effects.

Recent Studies

• A recent study published in 2024 found that low-dose oral minoxidil may be as effective and safe as standard topical minoxidil in treating androgenetic alopecia 3.
• However, another study published in 2023 found that the combination of topical minoxidil and platelet-rich plasma (PRP) was not superior to topical minoxidil alone in treating female pattern hair loss 4.
• The most recent and highest quality study should be prioritized when making treatment decisions, and in this case, the 2024 study suggests that oral minoxidil may be a viable alternative to topical minoxidil 3.