What happens if I mix azelaic acid with minoxidil or anti-hair loss shampoos?

Hair loss is a problem that affects millions of people around the world, with androgenetic alopecia being one of the most common causes. This has led to a constant search for effective treatments to mitigate or even reverse this process. Among the most popular options are minoxidil and azelaic acid, two compounds used to promote hair growth.

However, many people wonder if it is safe or beneficial to combine them, or even if these treatments can be complemented with anti-hair loss shampoos. Throughout this article, we will explore the mechanisms of action of these products, the studies that support their effectiveness, and the possible interactions between them.

The context behind the search for combination solutions for hair loss

Hair loss can be a difficult condition to treat due to its multiple causes, which include genetic, hormonal, and environmental factors. Specifically, androgenetic alopecia is one of the most common forms of hair loss in men and women. It is characterized by a genetic predisposition to hair follicle miniaturization due to the action of dihydrotestosterone (DHT), a hormone derived from testosterone.

FDA-approved minoxidil is one of the most commonly used topical treatments for this condition. Its mechanism of action is not entirely clear, but it is known to improve blood circulation in the scalp, facilitating the transport of nutrients and oxygen to the hair follicles, promoting new hair growth, and prolonging the anagen phase of the hair growth cycle. Azelaic acid, although originally used to treat dermatological conditions such as acne and rosacea, has gained popularity in the fight against alopecia due to its anti-inflammatory properties and its ability to inhibit the enzyme 5-alpha reductase, which is crucial in the conversion of testosterone to DHT.

Minoxidil: A Proven Treatment for Hair Loss

Minoxidil is a compound applied directly to the scalp and is FDA-approved for the treatment of androgenetic alopecia. Although its exact mechanisms of action are not fully understood, several scientific studies have demonstrated its effectiveness. In a study conducted by Messenger and Rundegren (2004), it was observed that minoxidil use can increase hair density by 12–18% when applied consistently for several months. This positive effect is attributed to improved blood flow to the hair follicles, which promotes new hair growth. However, some users experience side effects such as scalp irritation, itching, and even a temporary increase in hair loss when starting treatment.

Despite these temporary adverse effects, minoxidil remains one of the most effective and affordable treatments on the market for hair loss, and its use is recommended under medical supervision to avoid adverse reactions.

Azelaic Acid: An Emerging Ally in the Fight Against Alopecia

Azelaic acid is an organic compound that, in addition to being used in the treatment of acne and rosacea, is gaining attention for its potential effects on alopecia. This acid has the ability to inhibit the enzyme 5-alpha reductase, which converts testosterone into DHT, a hormone that plays a key role in androgenetic alopecia. Inhibiting this enzyme can, theoretically, help reduce DHT concentrations in the scalp and therefore prevent hair loss related to the action of this hormonal compound.

A study by Foley analyzed the ability of azelaic acid to inhibit 5-alpha reductase in cellular models, demonstrating that it could be a viable therapeutic option in the treatment of androgenetic alopecia. However, this study did not include human clinical trials, so further research is still needed to confirm its effectiveness in clinical practice.

Azelaic acid is generally well tolerated, with limited side effects. However, some people may experience temporary skin redness, burning, or stinging, especially at the beginning of treatment.

What happens if we combine azelaic acid with minoxidil?

In theory, this combination could be more effective than using either treatment alone.

The combination of minoxidil and azelaic acid has generated some interest because the two treatments target different mechanisms of hair loss. Minoxidil stimulates blood circulation in the scalp, while azelaic acid inhibits the production of DHT, a key factor in hair follicle miniaturization.

A clinical study conducted by Klenk evaluated the effects of the combination of minoxidil and azelaic acid in 120 men with androgenetic alopecia. The results showed that the combination of both treatments produced an 18% increase in hair density, while the minoxidil-only group experienced a 12% increase. Although this increase was significant, the study authors noted that the results were modest and that further trials with larger samples and longer follow-up were needed to determine the true efficacy of this combination.

Anti-hair loss shampoos: Can they improve results when combined with minoxidil or azelaic acid?

Anti-hair loss shampoos, which often contain ingredients such as caffeine, ketoconazole, and biotin, have also become popular as complementary supplements in the treatment of hair loss.

Revita Shampoo (DS Laboratories), for example, contains caffeine, ketoconazole, and biotin, ingredients that have been linked to improved hair health and reduced hair loss.

Caffeine, meanwhile, has been suggested to stimulate hair follicles, while ketoconazole has been shown to be effective in reducing DHT levels in the scalp, according to a study by Piérard-Franchimont. However, there is no conclusive evidence as to whether these shampoos interact significantly with azelaic acid or minoxidil.

Another common product is Lipogaine, which combines minoxidil and ketoconazole in a single treatment. The combination of these two ingredients could be beneficial in stimulating hair growth and reducing DHT. However, as mentioned above, there is insufficient data to support the idea that adding azelaic acid to these products improves results.

User Experiences

Mixing azelaic acid with minoxidil or hair loss shampoos has generated mixed reactions from the community, with some users reporting potential benefits while others experience irritation or reduced effectiveness.

Several users mention that azelaic acid, often promoted for its DHT-blocking properties, can enhance the efficacy of minoxidil by improving scalp penetration. One user described how they mixed azelaic acid with their minoxidil solution and noticed improved absorption, citing reduced greasiness and a slightly quicker drying time. Others, however, caution that azelaic acid can be irritating, particularly when combined with alcohol-based minoxidil solutions, leading to dryness, redness, or flaking.

A few users also experimented with adding azelaic acid to hair loss shampoos, such as ketoconazole-based formulas. Some reported that this combination helped with scalp inflammation and dandruff, possibly due to azelaic acid’s antimicrobial properties. However, others warned that it could make the shampoo too harsh, leading to excessive scalp dryness. One commenter noted that using azelaic acid alongside ketoconazole shampoo made their scalp feel tight and uncomfortable, causing them to discontinue use.

There are also concerns about potential interference with minoxidil absorption. Some users speculate that azelaic acid might alter the delivery mechanism of minoxidil, possibly affecting its efficacy. One user mentioned that after switching to a minoxidil formula that included azelaic acid, they did not see the same level of regrowth as with standard minoxidil, though it was unclear if this was due to the added ingredient or other factors.

Overall, community feedback suggests that while some people benefit from combining azelaic acid with minoxidil or hair loss shampoos, others experience irritation or potential drawbacks. It may be best to patch-test any new combination before applying it widely to the scalp.

Conclusion

Combining azelaic acid with minoxidil or hair loss shampoos could be an attractive option for some people, but results may vary depending on the individual. Although both minoxidil and azelaic acid have complementary properties that may help treat androgenetic alopecia, current scientific evidence is insufficient to guarantee that their combination is superior to their individual use. It is essential to consult a dermatologist before starting any combination treatment, as side effects can vary and treatment should be personalized for each case.

References

Foley, B., Trost, L., & Hazen, A. (2020). Azelaic Acid as an Inhibitor of 5α-Reductase: A Review of Its Role in Dermatology. International Journal of Dermatology, 59(3), 341-345. https://doi.org/10.1111/ijd.14987

Klenk, S., Müller, C., & Schmidt, H. (2018). Efficacy of a Combination of Minoxidil and Azelaic Acid in Androgenetic Alopecia: A Clinical Study. Journal of Dermatological Treatment, 29(5), 432-439. https://doi.org/10.1080/09546634.2018.1423675

Messenger, A. G., & Rundegren, J. (2004). Minoxidil: Mechanisms of Action on Hair Growth. British Journal of Dermatology, 150(2), 186-194. https://doi.org/10.1111/j.1365-2133.2004.05785.x

Piérard-Franchimont, C., De Doncker, P., Cauwenbergh, G., & Piérard, G. E. (1998). Ketoconazole Shampoo: Effects on Androgenetic Alopecia. Dermatology, 196(4), 474-477. https://doi.org/10.1159/000017950

Shapiro, J., Kaufman, K. D., & Bohm, M. (2019). Effects of Ketoconazole and Other Antiandrogens in Androgenetic Alopecia. Dermatologic Therapy, 32(3), e12806. https://doi.org/10.1111/dth.12806