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Caffeine Hair Growth Products...Cool...But do they work?
Caffeine and androgenic alopecia...
Now I'm a major coffee drinker. You could even say I'm dependent on that caffeine to super charge me for the day. So when I first heard that caffeine may actually promote hair growth I thought...Hmmm...
With the amount of chocolate I eat...Plus the amount of coffee and green tea I drink... Shouldn't I be over here looking like Rapunzel?
Before clicking "add to cart" on all of the caffeine infused topicals, oils, shampoos, and conditioners I decided to pause and do some research.
But before we dive in...If you're interested in hair loss treatments beyond caffeine check out some of my other posts linked HERE.
Now back to our program...
Here's what we'll review in this post:
Proposed mechanism of action. How is caffeine thought to work in promoting hair growth?
Talk data to me. A review of some of the clinical studies that use caffeine and assess hair growth
Things you may want to consider when evaluating these caffeine hair growth product studies
Caffeine Products for Hair Loss: Some Proposed Mechanisms
For this part I'm giving a simplified summary. See reference 8 below for a great overview of the caffeine studies performed in vitro, in vivo, and ex vivo.
Caffeine may counteract testosterone/dihydrotestosterone-induced miniaturization of the hair follicle (1)
May stimulate hair follicle growth and reverse testosterone-induced hair follicle growth suppression (2)
Caffeine also resulted in increased expression of insulin-like growth factor-1, a promoter of hair growth, in both male and female hair follicles (3)
The topical treatment of caffeine is thought to be promising because of its good follicular penetration and absorption (4)
Caffeine Hair Growth Products you may be familiar with
These are some of the caffeine products you might be familiar with. Many of them claim to impact things like hair growth and hair thickness.
But what do the clinical studies tell us? That's what I am always most interested in.
I did find some studies using topicals, and shampoos that have been studied in a clinical setting. But the majority of these studies (which used the caffeine hair growth products Alpecin and Plantur) were funded by Dr. Kurt Wolff GmbH---who also developed those products. This raises a red flag for me. I always wonder about the bias that may be introduced because of this.
Alpecin is marketed towards men whereas the Plantur products are marketed towards women.
In 2018 the advertising standards authority actually banned Alpecin from making claims it can help to reduce hair loss (7).
We will discuss one of the Alpecin studies in more detail below. I chose this study because it goes up against minoxidil. But I encourage you to do your own research as well and look out for who was funding the studies.
Talk Data To Me: Caffeine Products for Hair Growth: Alpecin
I have linked some of the Alpecin products I've found above.
The following study was an open-label Randomized Multicenter Study Assessing the Non inferiority of a Caffeine-Based Topical Liquid 0.2% (Alpecin) versus Minoxidil 5% Solution in Male Androgenetic Alopecia (5).
Stalk the study HERE.
What is an open-label study? The patients and the health providers are aware of the treatment being given. (More on this below).
Caffeine Group: Males with androgenic alopecia in the 0.2% caffeine solution arm applied 2 mL of the caffeine based lotion to the scalp twice a day (once in the morning and once in the evening)
Minoxidil Group: Males with androgenic alopecia in the minoxidil 5% solution arm applied 1 mL of the Minoxidil to the scalp twice a day (once in the morning and once in the evening).
Treatment period was 6 months
The results at 6 months were evaluated by trichogram which is the microscopic examination of hairs plucked from the scalp.
Trichogram provides info about the hair root and tip. This information can help in determining what phase the hair is in: anagen, telogen, or catagen phase.
Need a refresher on the hair cycle phases?
Anagen phase: Active growth phase of hair follicles Scalp hair normally stays in this active phase of growth for years
Catagen phase: At this phase the hair growth stops and the follicle is in the resting phase
Telogen phase: The hair shaft matures and is then shed from the follicle to prep for the start of a new cycle
Results: At 6 months, the men on the 5% minoxidil solution showed a mean improvement in anagen ratio of the trichogram of 11.68%, and the group of the 0.2% caffeine solution had an anagen improvement of 10.59%.
So this means there was no significant difference between both treatment groups.
When making sense of the results you may want to keep in mind that a proposed mechanism for how minoxidil works is that it may be causing premature termination of the telogen phase and prolonging the anagen phase (6).
And the authors of this study also see anagen phase improvement in both caffeine and minoxidil groups.
The authors concluded: A caffeine-based topical liquid should be considered as not inferior to minoxidil 5% solution in men with androgenic alopecia.
Some things you may want to consider about the above study
What concerned me when evaluating these results was that this was an open-label study.
When I'm evaluating data I typically look to see that the investigators and the recipients of the treatment are blinded to which treatment arm they're being assigned to. This reduces bias.
Dr. Kurt Wolff GmbH & Co. KG funded this study and Dr. Kurt Wolff is also the developer of the test product, 0.2% caffeine solution, which is marketed as Alpecin Liquid.
In my opinion this may open up even more potential for biased results.
Other studies using Plantur and Alpecin products are called out below.
Reference 9: This was a double-blind randomized clinical trial in females with androgenic alopecia. A caffeine shampoo was compared to placebo and efficacy was assessed. The study found significantly fewer hairs pulled in the caffeine treatment arm compared to placebo...This study also used patient questionnaires to evaluate hair loss intensity and found significant improvement.
Reference 10: Role of a caffeine shampoo in cosmetic management of Telogen effluvium. This study used the hair pull test to assess effectiveness in 30 women with telogen effluvium who used the shampoo... Results from the hair pull test were significantly fewer hairs pulled compared to at the start of the study. Study was 6 months in duration. The patients also answered questionnaires and it was found that there was a significant reduction in patient reported hair loss intensity.
Sum It All Up...Caffeine Products for Hair Growth
So what's the verdict... You've seen some of the pre-clinical and clinical data...In my opinion I don't think the clinical evidence is compelling enough for me to want to make a change in my treatment regimen.
I have concerns that many of these clinical studies are being funded by the makers of the caffeine product being tested. I also question the design of some of these studies like the open-label one we discussed above
I have concerns about the way efficacy is being measured. Many of these studies are using the "hair pull test." A concern with this type of assessment is that it is difficult to standardize. There's variation in each pull force and then this force isn't distributed evenly across the whole hair bundle (12)
Some of the in vitro data doesn't add up for me either. For example one of the follicular penetration studies for caffeine shampoo is being evaluated on chest hair (13). Why not the scalp?
I think based on everything I've read I'll hold off on caffeine products for hair growth. I just don't think the clinical data supports its efficacy. But I encourage you to do your own research as well. And always consult with your doctor before making any changes to your hair loss treatment regimen!
Thank you so much for reading! Don't forget to subscribe to make sure you never miss a post!
xoxoxo
-Riley
References:
1) Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro. Fischer TW, Hipler UC, Elsner PInt J Dermatol. 2007 Jan; 46(1):27-35.
2) Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro. Fischer TW, Hipler UC, Elsner P Int J Dermatol. 2007 Jan; 46(1):27-35.
3) Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and transforming growth factor-β2/insulin-like growth factor-1-mediated regulation of the hair cycle in male and female human hair follicles in vitro. Fischer TW, Herczeg-Lisztes E, Funk W, Zillikens D, Bíró T, Paus R Br J Dermatol. 2014 Nov; 171(5):1031-43.
4) Development of an in vitro modified skin absorption test for the investigation of the follicular penetration pathway of caffeine. Trauer S, Lademann J, Knorr F, Richter H, Liebsch M, Rozycki C, Balizs G, Büttemeyer R, Linscheid M, Patzelt A Skin Pharmacol Physiol. 2010; 23(6):320-7.
5) Dhurat R, Chitallia J, May TW, et al. An Open-Label Randomized Multicenter Study Assessing the Noninferiority of a Caffeine-Based Topical Liquid 0.2% versus Minoxidil 5% Solution in Male Androgenetic Alopecia. Skin Pharmacol Physiol. 2017;30(6):298-305. doi:10.1159/000481141
6) Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro. Fischer TW, Hipler UC, Elsner P Int J Dermatol. 2007 Jan; 46(1):27-35.
7) https://www.independent.co.uk/news/uk/home-news/alpecin-caffeine-shampoo-banned-reduce-hair-loss-advertising-standards-authority-a8276951.html
8) Völker J, M, Koch N, Becker M, Klenk A: Caffeine and Its Pharmacological Benefits in the Management of Androgenetic Alopecia: A Review. Skin Pharmacol Physiol 2020;33:153-169. doi: 10.1159/000508228
9) Bussoletti C, Tolaini MV, Celleno L. Efficacy of a cosmetic phyto-caffeine shampoo in female androgenetic alopecia. G Ital Dermatol Venereol. 2018 10)
11) Sisto T, Bussoletti C, Celleno L. Role of a caffeine shampoo in cosmetic management of telogen effluvium. J Appl Cosmetol. 2013; 31:139–45
12) Assessment of hair loss: clinical relevance of hair growth evaluation methods. Van Neste MD Clin Exp Dermatol. 2002 Jul; 27(5):358-65.
13) Otberg N, Teichmann A, Rasuljev U, Sinkgraven R, Sterry W, Lademann J. Follicular penetration of topically applied caffeine via a shampoo formulation. Skin Pharmacol Physiol. 2007; 20(4):195–8