Caffeine is almost everywhere these days. This article will go deep into the science of whether caffeine causes hair loss or hair growth and how it can do both.
Whether it is a beverage like coffee or sports drink, or in shampoos, after reading this article you will know how and why to use caffeine to your advantage so you can achieve thicker, stronger hair and a lower hairline.
What is Caffeine?
Caffeine is a bitter, white crystalline stimulant that belongs to a group of naturally-occurring alkaloids of the methylxanthine class. It is mostly found in coffee, tea, kola nuts, and cacao beans.
According to the Food and Drug Administration, caffeine is used in both prescription and over-the-counter medicines to treat drowsiness, and it is also known to work well alongside pain relievers.
For these reasons, caffeine is very popular among people of all ages, and chances are you have consumed it frequently.
How Caffeine Can Benefit Your Hair
Here is a closer look at the benefits of topical caffeine use for hair growth.
It Helps to Suppress DHT
Research has revealed that caffeine is an effective suppressant of androgenetic alopecia (AGA), commonly known as male pattern baldness (1).
The biopsies were taken from 14 male patients, ranging in age from 20 to 45. Each patient was classified between a Stage III and IV on the Norwood-Hamilton scale for hair loss.
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The cultivated hair follicles were split into three groups: control (which contained various levels of testosterone), caffeine (which contained various levels), and both (cultivated in testosterone first and then cultivated in caffeine in various concentrations).
After a period of 120 to 192 hours, the follicles were removed and researchers studied hair shaft length to determine the efficacy of caffeine.
The longer the follicle was exposed to caffeine, the longer the hair shaft became. There was even a slight difference in the elongation effects of the two different concentrations (0.001% and 0.005%), though it is quite negligible.
However, this was not the only thing that researchers found.
Surprisingly, hair follicles that were exposed to caffeine even after exposure to testosterone showed positive (and significant) elongation:
Addition of caffeine in amounts as small as 0.001% was found to counteract the suppressive effects of testosterone on hair growth with higher shaft elongation achieved compared to the control group.
It Stimulates Hair Growth
Even more than suppressing the effects of DHT, caffeine has been shown to stimulate hair growth in human hair follicles (3).
Whole human hair follicles were extracted from the scalps of both men and women. The men were confirmed to be a stage III to stage IV on the Norwood-Hamilton scale while the women were ‘normal’.
After a 24-hour recovery time, the hair follicles were cultivated in one of three mediums:
- Testosterone only;
- Testosterone + caffeine; or
- Normal medium (as a control).
The total culture time was 120 hours.
Here is what the study found.
Caffeine Enhanced Hair Shaft Elongation
Just as the previous study showed, the presence of caffeine even after the hair follicle has been exposed to testosterone can elongate the shaft.
Interestingly, this elongation was shown to be different between men and women.
In the previous study, concentrations of caffeine as low as 0.001% were found to be effective in counteracting the effects of testosterone. However, these were shown to be too high for women, and the concentration was lowered to 0.0005%. This proved to be beneficial, and results were shown to be similar to those of male hair follicles.
Caffeine Prolonged Anagen Phase
There are three stages within the hair growth cycle:
- Anagen (active growth);
- Catagen (transition); and
- Telogen (rest).
In men and women with AGA, the process of follicle miniaturization shortens the anagen phase. This results in less hair growth.
By prolonging the anagen phase, the effects of DHT (which trigger miniaturization) can be counteracted. As shown by researchers, this is exactly what caffeine was able to do:
When exposed to testosterone, the percentage of male and female hair follicles in the anagen phase reduced dramatically (to 39% and 55%, respectively). When coincubated with caffeine, though, these percentages raised to 70% in men and to 63% and 65% in women.
This shows that caffeine can not only suppress DHT, but it can also make it possible for the hair follicles to function even in its presence.
Caffeine Stimulated Hair Matrix Keratinocyte Proliferation
The hair follicle is a complex organ containing multiple parts that work together to produce hairs from the skin. One major component of the follicle is the hair matrix, which is where the hair shaft (and the inner and outer root sheaths) are actually produced.
Within the matrix are cells tasked with producing keratin, the protein that makes up the majority component of hair. One major finding within this study was that caffeine actually stimulated the proliferation of keratinocytes.
The above shows an increase in the presence of Ki-67, a protein that marks cellular proliferation (4). As the concentration of caffeine goes up, so too does the amount of Ki-67 present within the follicles.
If keratin is necessary for the growth of hair, then an increased presence of keratin-producing cells can be beneficial during the anagen phase of hair growth. This can lead to more hairs being produced over time.
It Can Be Absorbed Through the Scalp
Researchers from Berlin, Germany, and Tashkent, Uzbekistan recruited six healthy, Caucasian men to take part in their study (5). The goal was to determine the ability of caffeine to penetrate the skin and absorb into the hair follicles.
The six volunteers underwent two separate experiments which took place one week apart:
- In the first experiment, a shampoo with caffeine (1%) was applied to a test area on their chest. The follicles in this area remained open.
- In the second experiment, a shampoo with caffeine (1%) was applied to a test area on their chest. The follicles were then closed with a varnish-wax mixture.
Each volunteer had their caffeine levels tested via blood test before beginning.
The shampoo was washed away after two minutes, and blood samples were taken at 5, 10, 20, and 30 minutes, as well as 1, 2, 5, 8, 24, and 72 hours after the caffeine shampoo application.
In the first group, it was found that caffeine levels could be detected in the blood as early as five minutes post-application. The concentration showed at 6.3 ng/ml.
In the second group, though, caffeine levels were only detected once 30 minutes had passed. Researchers theorized that the inability to permeate the follicles significantly slowed its absorption (as its only way through was the skin).
This shows that, when in the presence of follicles, caffeine is able to be significantly absorbed.
What Amount of Caffeine is Healthy for Your Hair?
Scientists estimate that you would have to consume about 60 cups of coffee (the main source of caffeine) for you to ensure that the amount reaching the hair follicles is significant.
However, that would be a detriment to your body and would put you at risk of a heart attack. It is also known to be addictive: if you take more than two cups a day, you can form a dependence and might experience headaches, anxiety, or even depression.
So, instead of taking caffeine in the form of drinks, a caffeine-rich solution rubbed on your scalp would be the best treatment for your hair. Luckily, there are caffeinated shampoos out there that you can readily buy.
A Simple Coffee Oil Shampoo
Coffee grounds can be dried and infused into oil which can be rubbed on the scalp either directly or when combined with pre-made shampoo treatments and leave-in conditioners.
- Green or roasted whole coffee beans (3 ounces)
- Coconut oil (3 cups)
- Pour the coconut oil into a small glass crock pot
- Add the 3 ounces of coffee beans
- Cover the beans and the oil and cook for approximately five to six hours over slow heat. Regular checks might be necessary to ensure the oil and the beans do not burn. Be sure to stir the mixture every half hour or so.
- When the mixture is cooked, turn off the crockpot and use a paper coffee filter to strain the oil and remove the beans which can now be disposed of.
- Pour the oil into a clean container, ready for use.
- Apply the oil directly to the scalp, either on its own or combined with shampoo, and leave it for five to eight minutes.
- Rinse thoroughly with plenty of cold water.
Which is Better: Consumption or Topical Application?
If you are not too keen on applying caffeine to your scalp, or you just want an excuse to consume more caffeine, you may be wondering if consumption is just as good as a topical application.
When it comes to hair growth, the answer is clear: topical application is best.
As highlighted above, topical application of caffeine has direct benefits to the hair follicles. Caffeine absorbs easily into the scalp, and this contributes to hair shaft elongation, DHT suppression, and more.
There is no evidence that it is possible to see these same benefits with moderate caffeine intake.
Caffeine Intake and Hair Loss: Too Much of a Good Thing?
You may have heard that consuming too much caffeine is bad for hair growth as it slows it down. There is not solid evidence to suggest whether consumption of caffeine is bad for hair growth, but too much of a good thing can have its own side effects.
When you consume caffeine in moderation, it has several health benefits.
There are risks to too much caffeine in your diet, however. These include restlessness, tremors, difficulty sleeping, and irregular heart rate.
So how much is too much? Like anything, this will depend on many factors.
The average caffeine intake for adults in the United States is 180 mg/day, or about two cups of coffee (6). For most individuals, this seems to be the sweet spot.
But there are populations that are more susceptible to the negative effects of caffeine consumption, so they may need to lower their intake. These include:
- Women who are pregnant or lactating
- Patients with mental illness
- People with underlying heart conditions
It is also possible to be more susceptible to caffeine’s effects without falling into one of the populations above. Caffeine tolerance does seem to be a genetic trait, so it is important to know what your tolerance levels are and abide by them (7).
There is overwhelming evidence that strongly suggests caffeine is a good natural product for your hair. Besides helping you to fight off scalp conditions like androgenetic alopecia, caffeine can help grow your hair quickly and also improve its vitality.
Its ability to penetrate the scalp pretty easily makes it a good addition to your favorite hair shampoo.