Which Minoxidil solution is better: 2%,5%, 10%, 15%?

Minoxidil is the only topical drug approve for the treatment of androgenic alopecia and is available in a variety of concentrations, including eight concentration modes of 1%, 2%, 3%, 5%, 7.5%, 10%, 12.5%, 15%, with the most commonly used concentrations being 2%, 5%, 10%, and 15%. Of the four modes of concentration – 2%, 5%, 10%, 15% – which is the best?

Comparison of treatment efficacy of Minoxidil solution at different concentrations

5% VS 2% minoxidil solution

In a 48-week placebo-controlled randomized double-blind trial in 2002, 393 patients were topically administer 5% and 2% minoxidil solution and their efficacy compare. Studies show that 5% minoxidil is significantly more effective than 2% in improving hair number and hair growth, and the treatment response of 5% minoxidil liquid observe earlier. In terms of side effects, it showed more itching and local irritation with 5% minoxidil liquid.

The study showed that 5% minoxidil was more effective than 2%.

5% VS 15% 

In 2020, a randomized self-comparing clinical trial involving 66 patients with androgenic alopecia evaluated the safety and efficacy of a 15% minoxidil liquid compared to a 5% minoxidil liquid. Participants were divided into two groups, one receiving a 5% minoxidil liquid and the other receiving a 15% minoxidil liquid for 24 weeks. At weeks 12 and 24, 15%  solution had significantly better hair growth than 5% .

In a 2016 trial in women with female alopecia, women with hair loss who did not respond to topical use of 5% minoxidil liquid had a clinically significant response observed in 60% of participants after 12 weeks of treatment with 15% minoxidil liquid. The trial demonstrated the use of minoxidil liquid in 15% of patients who did not respond to the 5% solution.

5% VS 10%

In 2021, a randomized, placebo-controlled, double-blind trial involving 90 patients with androgenic alopecia validated Minoxidil’s effectiveness in improving hair regeneration.

The trial divided participants into three groups, with the first group receiving 10% , the second group receiving 5% minoxidil liquid, and the third group receiving placebo. After 36 weeks, the patients in the 5% minoxidil liquid group had significantly more hair than the other two groups, demonstrating that the 5% minoxidil liquid worked better than the 10% minoxidil liquid.

Sum up

Through the above tests, we can see that 5% minoxidil solution is the best in practical use. People who do not respond to 5% minoxidil and try treatment with a higher concentration (such as 15% minoxidil liquid) will see results again.However, there may be more side effects if you directly use a 15% .

In a previous article on making minoxidil solution, we learned that minoxidil has a solubility of 75mg/ml in propylene glycol, 29mg/ml in ethanol, and 2.2mg/ml in water, respectively. When make a minoxidil solution with a concentration of more than 7.5%, its solubility tends to saturate, and minoxidil is more easy oxidize during use, which affects actual performance. Therefore, 5% is the most appropriate ratio of minoxidil liquid.