Caffeine, the active component of coffee, has been featuring in hair growth and skin care products for over a decade. The increasing prominence seems justified when you look at the results and outcomes of the studies around caffeine and its effect on hair. The main mechanism of work has a lot to do with the counteractive effect caffeine has on DHT (dihydrotestosterone) conversion in hair follicles which otherwise would lead to their miniaturisation by promoting proliferation of. In fact, knowing of this effect, is what led us to include caffeine in The Hair Fuel hair growth mask. Today, we take a deep dive to understand the link between caffeine and hair growth and how it can help with hair loss.
What is Caffeine?
Caffeine is a stimulant: a bitter, white crystalline organic water soluble compound, a methylxanthine alkaloid. It also world’s widest consumed psychoactive drug (!).
Caffeine exists in the seeds, nuts, or leaves of a number of plants native to Africa, East Asia and South America. This helps these plants to protect against predator insects and to prevent germination of nearby seeds. The most well-known source of caffeine is the coffee bean. Naturally occurred caffeine is also contained in various tea leaves including mate, green and black tea, cacao beans, guayusa – an Amazonian plant, and guarana berries.
Caffeine and hair growth
Let’s clarify something from the outset – drinking coffee is not going to help your grow your hair. We would need an equivalent of 50-60 cups of coffee in order to produce noticeable hair-growing results – the amount which is unsafe and dangerous for your health, and is NOT what you should do. It could cause seizures and be extremely harmful to your body and would put you at risk of a heart attack.
Coffee consumed orally is also addictive: if you take more than two cups a day, you can form a dependence and might experience headaches, anxiety, and depression as a result.
A number of studies, however, had shown that the hair follicle absorbs caffeine directly and does so with ease.
Thus, topically applied caffeine is what your scalp needs for it to grow healthy hair. This explains the logic behind tea rinses and coffee grounds scrubs for your scalp – both of which make sense from the standpoint of studies referenced in this article.
How does caffeine impact hair follicles?
Androgenetic alopecia (AGA) is a common form of hair loss amongst men and women – linked to testosterone being converted to a dihydrotestosterone (DHT) molecule.
DHT does a great job in dealing with local inflammation in scalp, but it also triggers hair minituarisation effect as a result of that, too. Amongst scalp calcification and scarring of the hair follicle’s lining, DHT destroys subcutaneous fat tissue in scalp, otherwise necessary for cushioning the hair follicle to reach blood supply in epidermis.
In simpler terms, DHT protects your scalp from inflammation but it makes your hair follicle smaller in the process.
Caffeine counteracts this miniaturising effect by inhibiting phosphodiesterase, an enzyme responsible for breaking bonds that otherwise facilitate cell signalling. Amongst such signals are those sent to the hair follicle to promote cell proliferation and therefore – hair growth. With caffeine blocking this enzyme from blocking the signals, cells, specifically keratinocytes, can multiply which leads to thickening of the hair bulb and extension of anagen – growth stage. In simpler words, this process leads to your hair growing longer and thicker.
One in-vitro by University of Lübeck in Germany studied samples from patients suffering from AGA and effect of treating hair follicles with testosterone and / or caffeine. Samples were cultivated with different concentrations of testosterone and/or caffeine for a period of 120-192 hours.
Fischer, Hipler and Elsner, the leading scientists of the study, took the biopsies of hair follicles from 14 male patients, ranging in age from 20 – 45. Each patient was at various stages of hair loss. Firstly, they treated cultivated hair follicles with various levels of testosterone, which, unsurprisingly, resulted in stunting hair growth. Afterwards the same hair follicles were treated with various caffeine levels, against a control (placebo) group.
The results of this experiment had shown, that not only caffeine cancelled out negative effects of testosterone on hair growth, but caffeine alone when applied to a un-treated with testosterone hair follicle – led to improvement in hair growth.
Results of caffeine hair treatment
In this study, caffeine treatment:
- Enhanced hair shaft elongation – i.e. making the hair root bigger.
- Prolonged anagen duration – i.e. increased hair growth stage.
- Stimulated hair matrix keratinocyte proliferation – i.e. produced more keratin – key structural component of human hair).
What is more astonishing, is that after a period of 120 – 192 hours, the hair follicles treated with caffeine continue to show faster hair growth than those untreated with caffeine. So the effects of caffeine are lasting after initial application.
Rather than going through digestive tract and affecting neurotransmitters that would otherwise affect your concentration and mood, blood pressure and potentially causing other harmful and addictive effects in our body – in this study, topically applied caffeine stimulated hair follicle directly that reduced hair loss and improved hair growth and hair health.
Would caffeine work for all hair?
Caffeine works with different efficacies for everyone. A largely identical group of scientists performed an additional study, this time on both, female and male hair follicles.
Female hair follicles exhibited greater perception and therefore better effects of caffeine on hair growth. This could be partially due to lower levels of androgens in females, which increases the net positive impact on hair follicle elongation and extension of anagen is greater.
Having said that, caffeine treatment in both, males and females, continue to show promising results in helping with hair loss, hair thickening and improvement of hair growth.
How do you apply caffeine for hair growth?
Tea rinses and ground coffee scrubs can help with hair growth through the same mechanism as described in the study: i.e. topical application.
Another study had shown that caffeine absorption takes 2 to 20 minutes after application. Meaning that in order to have caffeine maximally absorbed by your follicle you need to be rinsing and / or scrubbing your hair for up to 20 minutes to derive maximum results of caffeine on your hair follicles to tackle hair loss and prompt hair growth.
How to make caffeine hair rinse:
- Tea rinse: make around 500ml of strong cup of black tea – 2 teabags steeped for 5-10 minutes should render desired concentration. Allow tea to cool. Rinse your hair with tea concentrate after your usual shampoo & conditioner routine, leave on your scalp for up to 20 minutes to ensure caffeine absorption by your hair follicles and rinse off.
- Coffee scrub: mix coffee grounds with warm oil of choice until desired creamy consistency, closer to that of a toothpaste – take our Hair Quiz to know which hair oil works best for you. Massage resulting coffee paste into your hair roots for 5-10 minutes. Rinse with warm water and follow with your usual shampoo + conditioner routine.
- Alternatively, there are other products, which not only contain caffeine, but also stimulate blood flow in scalp for hair growth in other ways by stimulating blood flow to the hair follicles.
The next time you’re enjoying a cup of your regular, celebrate this magical plant which can lift your mood AND your hair roots. Or better yet, combine your next cup of joe with an invigorating self-care routine: a face mask and caffeine-based hair treatment on a weekend morning.
Who we are:
The Hair Fuel is an all-natural hair growth mask created by Laura Sagen, who lost a third of her hair after a terrible visit to a hairdresser while suffering from a life-long condition of PCOS associated with androgenic hair thinning. She developed the formulation rooted in science of scalp blood flow, which has become The Hair Fuel growth mask. Since then, her company has helped thousands of people like you to start growing healthy hair.
We work closely with our lab and manufacturers to ensure the highest quality product. But a product alone is never enough – so we hold your hand throughout your own, unique hair growth journey. Our flagship product, The Hair Fuel mask coupled with tailored advice, digital tools and online support are there to help you grow the best hair you can. It’s a big claim – but we’re unafraid to make it. Check out our starter bundles >>
Effect of caffeine and testosterone on the proliferation of human hair follicles in vitro, International Journal of Dermatology, (1)
Follicular Penetration of Topically Applied Caffeine via a Shampoo Formulation, (2)
Differential effects of caffeine on hair shaft elongation, matrix and outer root sheath keratinocyte proliferation, and transforming growth factor‐beta2/insulin‐like growth factor‐1‐mediated regulation of the hair cycle in male and female human hair follicles in vitro (3)
Increased cAMP levels in human hair follicles due to local treatment with trichoriboside (4)
1. How fast does caffeine grow your hair?
Average human hair growth on scalp is approximately 0.5 inch / 1 cm a month, in combination with other ingredients, caffeine can result in a triple acceleration of hair growth.
2. Does caffeine thicken hair?
Topically applied caffeine to scalp is shown to elongate the hair follicle, thus resulting in overall thicker hair. Having said that, concentration of caffeine must be low enough to act as a vasodilator and muscle relaxant, so as not to stimulate the opposite effect of caffeine as a vasoconstrictor.
3. Is caffeine bad for hair?
In high concentrations (higher than 0.01% per solution) caffeine is shown to have a suppressing effect on keratinocyte proliferation in hair follicles – in other words, high concentration of caffeine can cause hair thinning due to restricted blood supply. Having said that, in low enough doses, caffeine has the opposite effect, acting as a stimulant for hair growth.
4. Does caffeine Work for hair loss?
In a number of peer-reviewed studies caffeine has shown to address hair thinning and androgenetic-related hair loss. However the concentration of caffeine must be low enough to produce such an effect. You must be careful because in higher concentrations of caffeine in a topical stimulant, you run a risk of worsening hair loss further.