Minoxidil: The side effects

Male pattern baldness can be a worrying issue for a lot of guys. It’s the most common form of hair loss, affecting about two-thirds of men by the age of 35, though it can begin a lot sooner. 

One of the most powerful treatments for hair loss is Minoxidil. It’s a topical treatment, meaning that you apply it directly to the scalp. It works wonders for up to 70% of men who take the treatment, with a significant difference in the degree of hair loss when applying the solution on a regular basis. Minoxidil often also increases hair density and in some cases can regrow hair where it has been lost.

How Does Minoxidil Work?

As mentioned above, Minoxidil is a solution which is applied directly to the scalp in order to combat hair loss. It is sold under many different trade names around the world including Rogaine ®.

The treatment dilates the blood vessels around your hair follicles. In turn, this increases the nutrient supply to them, supporting the hair follicles to grow thicker and stronger hair. The treatment is most effective when you’re experiencing hair thinning on the crown of the head, as it helps regrow hair and prevent bald spots.

The treatment is one of only two treatments which have been scientifically proven to effectively combat hair loss – the other is Finasteride. 

How Effective is Minoxidil?

Don’t just take our word for it – there are many scientific studies which have proven that Minoxidil is an effective treatment for hair loss. 

A 2003 study which looked at the effectiveness of Minoxidil over a period of four months showed that 74% of men considered Minoxidil to have improved their hair density. In addition, 93.8% of the study participants judged Minoxidil as ‘very effective’, ‘effective’ or ‘moderately effective’ at stimulating new hair growth.

The strength of Minoxidil used is also a factor in its effectiveness. In a 2002 study,  5%-strength Minoxidil was shown to be significantly more effective than 2% Minoxidil when measured at 8 weeks as well as 48 weeks.

We’ve collected the results of a range of studies on Minoxidil here.

Minoxidil Side Effects

Minoxidil has a high success rate in treating hair loss as a result of male pattern baldness, and it’s also very easy to use. However, as with any medicine, side effects from Minoxidil are possible, but rare.

Most often, these unpleasant side effects are caused not by the Minoxidil itself, but by the harsh additives and preservatives that make up the treatment, including ethanol (alcohol) and propylene glycol (PG). We’ve given you all the information about possible side effects below.

Hair Shedding

A lot of guys experience hair shedding once they start taking Minoxidil, but although we’ve included this here, it isn’t actually a negative side effect. You will probably experience some hair shedding when you first start to use Minoxidil. But this is perfectly normal, and not a reason to worry. The shedding is caused by your hair follicles growing out new healthier hairs, and this makes some of the old hairs fall out – hairs that were due to fall out soon anyway. 

Itchy skin / skin irritation

Skin irritation, which is sometimes associated with Minoxidil use, is usually caused by other ingredients used in the Minoxidil solution, such as ethanol (alcohol).


This is something that you should consult a professional about before you start taking any new treatments. 

Weight gain

Though it is rare, in some cases men have complained of an increase in their weight after taking Minoxidil. This is caused by an increase in water retention, which can also lead to swelling in their hands and feet.

Sexual side effects

In some very rare cases, men who have taken Minoxidil have complained of sexual side effects such as reduced libido and erectile dysfunction. 

However, a study in 2014 concluded that there was still “no confirmed evidence” that Minoxidil negatively affects the male libido.

Headaches or dizziness

Headaches have been reported by some men using Minoxidil. If you experience these side effects for a continued period, you should seek advice from your GP immediately.


5% Minoxidil solution has been proven to be the most effective for treating male pattern hair loss. Scientific studies have shown that anything higher than this level is not proven to be more effective.

How to Use Minoxidil (Safely)

The best way to use Minoxidil safely is to follow the guidelines, which we’ve outlined for you below:


Apply 1 ml of the solution directly onto your scalp twice daily (once in the morning and once at night), using the dropper provided. 

If you miss an application one day, don’t worry, just carry on with the treatment the next day as if you had not missed the application.

You must not use more than 2 ml of the solution in 24 hours. 

You must not use any more than this amount, even if you don’t notice results straight away. If you don’t see results within 6 months of use, consider speaking to your doctor about stopping the treatment.

Before usage

Before you use the dropper, make sure that your scalp is dry or towel-dry. You don’t need to wash your hair before applying the solution.

After usage

After applying the treatment, allow at least a few minutes for the solution to dry before touching your scalp against other materials, such as a hat or a pillow case.

Minoxidil is a hair loss treatment for external use only and should only be applied directly to the scalp.

Storing Minoxidil

It’s important that you store your medicine properly, so that it remains both effective and safe to use throughout the course of your treatment.

  • Keep out of the sight and reach of children

  • Do not use this medicine after the expiry date printed on the bottle.

  • Store upright, below 25°C and protect from light.

  • When the bottle is empty, the bottle and applicators must be disposed of safely.

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This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment or medication.

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