Caffeine and its Impact on Hair Loss
Written by: Patricia Shelton, MD
How does topical caffeine help with hair loss?
Hair loss is a very common problem, which can affect both men and women as they age. Many people are looking for a solution, and they’re often hoping for something that’s natural and nontoxic, with as few side effects as possible. Recent research has shown that a hair loss solution like this is not only possible, but it could actually be found in something that many people actually consume regularly – caffeine.
Caffeine is a surprisingly common molecule. In fact, more than 60 different species of plants are known to synthesize caffeine. People have been consuming this substance (usually in forms like coffee, tea, or chocolate) for thousands of years, giving it an excellent track record of being nontoxic. In fact, studies suggest that regular consumption of caffeine may have a number of health benefits, including a reduced risk of dementia, cancer, and diabetes.
Caffeine’s long history of use, low toxicity level, and potential health benefits are all desirable qualities. But of course, the most important question is whether caffeine actually works for hair loss. A number of studies have shown that it does. In the laboratory, caffeine has been found to both enlarge hair follicles and lengthen their growth phase.
When it’s used for hair loss, caffeine is given as a topical treatment (most commonly, it’s included in a shampoo). This allows the delivery of high doses of caffeine to hair follicles, with minimal to no side effects in the rest of the body. Multiple studies have shown that regularly applying caffeine to the scalp is beneficial for hair loss. After six months, people who use a caffeine-containing shampoo daily show a reduction in hair loss and an increase in hair thickness.
What are the effects of caffeine on hair follicles?
To look at the effects of caffeine on hair follicles, one study transplanted individual hair follicles from 14 men into a culture in the laboratory. This allowed researchers to control the follicles’ environment. The follicles were exposed to testosterone. It’s well-known that testosterone (or a form of it known as dihydrotestosterone, or DHT) reduces hair growth; this is believed to be a major mechanism for age-related hair loss in men, and possibly in women as well. The study found this effect, as expected. Follicles exposed to testosterone showed reduced growth.
Next, the follicles were exposed to caffeine along with the testosterone. The caffeine actually blocked testosterone’s effect on the hair follicles. This allowed for a higher growth rate in the follicles that were exposed to both caffeine and testosterone. In fact, follicles that were exposed to caffeine and not to testosterone showed a higher growth rate than those that were simply left alone, further demonstrating the ability of caffeine to promote hair growth.
How does caffeine affect hair growth?
Every hair follicle goes through a regular series of phases. During the follicle’s growth phase, new hair is produced. In healthy hair, this phase can last for a few years. The hair follicle then transitions to a resting phase. The old hair falls out, and the follicle stays empty for a period of time, before entering the growth phase again.
In people with male pattern or female pattern hair loss, the follicles gradually develop a shorter growth phase and a longer resting phase. This transitions to fewer hairs on the head at any given time. In order to address this issue, we need to increase the amount of time that each follicle spends in the growth phase.
There are a number of different signaling molecules that the body uses to regulate the phases of each hair follicle. Studies in the laboratory have shown that caffeine has a direct effect on some of these signaling molecules. Because of this effect, caffeine stimulates the hair follicle to remain in the growing phase for longer. This translates to a reduction in hair loss.
Is caffeine actually effective for hair loss?
Although laboratory experiments may be interesting, what most people really want to know is whether the treatment actually works in the real world. What happens when people experiencing hair loss use topical caffeine? Do we have evidence that it’s effective?
In fact, we have quite a few studies showing that topical caffeine is effective for hair loss. There have even been randomized controlled trials of caffeine, which is the highest level of scientific evidence for a treatment’s effectiveness. One such study looked at 66 men with male pattern hair loss. They used topical caffeine (or a placebo, which is an inert substance used for comparison), in the form of a shampoo, for six months.
By the end of the study, those who used the topical caffeine had a significant reduction in hair loss, along with improvement in the strength and thickness of their hair. These effects were seen in reports by the investigators as well as by the subjects themselves, indicating that the results were robust.
Studies in women have also shown that caffeine is an effective treatment for female pattern hair loss. The use of a caffeine-containing shampoo for six months led to a reduction in hair loss and an increase in hair strength.
Why is caffeine used topically for hair loss?
When used for hair loss, caffeine is generally applied topically (meaning that it’s used in the form of a lotion that’s applied to the scalp) rather than taken orally (in the form of a pill). The main reason for this is that the dose of caffeine that’s needed to stimulate hair growth is quite high compared to the amount that’s in a cup of coffee. In fact, you would need dozens of cups of coffee to get enough caffeine to your hair follicles to make a difference. This is clearly an unworkable solution, as it would cause severe side effects. Applying caffeine directly to the scalp is a far safer option.
Caffeine is a very small molecule, which allows it to penetrate easily into the tissues of the scalp. This allows you to get a high enough concentration of caffeine in the hair follicles and surrounding tissues to have a significant effect. With some other topical treatments, the molecules may be too large to penetrate into the skin, and this limits their effectiveness. Because caffeine is such a small molecule, this isn’t a problem.
Studies have shown that when a caffeine-containing shampoo is applied to the scalp for just two minutes, significant concentrations of caffeine make it into the tissues of the scalp. In fact, caffeine can still be detected in the scalp 24 hours later. By using caffeine-containing shampoo once a day, a significant level of caffeine can be maintained in the scalp.
Using caffeine as a topical treatment allows you to treat the hair follicles with a high enough dose to be effective, without experiencing the severe side effects that this dose would cause if taken orally.
How does topical caffeine compare to other hair loss treatments?
Currently, we have just a few other effective options for hair loss. Finasteride and minoxidil are both FDA-approved for hair loss. In both cases, topical as well as oral versions are available.
There was a study directly comparing topical caffeine to topical minoxidil. A group of 210 men each used one of these two treatments daily. After six months, both groups had experienced increased hair growth, with less hair loss and an increase in hair thickness. The two treatments showed very similar results, indicating that topical caffeine could be a good alternative to minoxidil for those patients who prefer a more natural alternative.
These treatments also don’t have to be mutually exclusive. It’s possible to use caffeine alongside other hair loss treatments. In fact, adding caffeine to other hair loss treatments has been found to increase their effectiveness. If you’d like to consider treatment for hair loss, it’s a good idea to discuss this with a qualified dermatologist, who can help you to decide among your various options and determine what’s right for you.