You’ve seen the adverts: “hair energizing”, “German-engineered” caffeine shampoo that prevents hair loss. Yes, the same compound found in coffee may prevent hair loss when applied to the scalp. At least that’s what the adverts claim – and there is some support for it. But is this evidence reliable? Does caffeine shampoo work for hair loss?
Why might caffeine prevent hair loss?
There is some evidence that caffeine may be beneficial for certain types of hair loss, including androgenetic alopecia (male pattern hair loss).
Alpecin, manufacturers of caffeine shampoo, use this 2007 study from the University of Jena to support the hair-stimulating properties of their product.
The study found that testosterone-induced hair growth suppression was reduced ex vivo when 0.001% and 0.005% concentrations of caffeine were used:
“Significant growth suppression was found in hair follicles treated with 5 microg/ml testosterone. This was counteracted by caffeine in concentrations of 0.001% and 0.005%. Moreover, caffeine alone led to a significant stimulation of hair follicle growth.”
Put simply, caffeine prevented the negative effects of testosterone on hair.
It’s not just that one study either. Alpecin has an entire list of studies it uses to support the benefits of caffeine for hair.
So there is evidence to support caffeine shampoo as a hair loss treatment.
However, as we’ll see, these studies aren’t entirely conclusive – especially when it comes to male pattern hair loss.
Why caffeine shampoo doesn’t work for male pattern hair loss
Despite the initial promise of the 2007 University of Jena study (above), it does not necessarily support the benefits of caffeine shampoo for male pattern baldness.
The first, and perhaps biggest, flaw is that the experiment was conducted ex vivo. Hair follicles used in the trial were removed from balding men and artificially grown in a laboratory.
And while the caffeine-treated follicles did indeed show better hair growth, it is questionable whether this same effect would be seen when used on actual human hair loss sufferers. Just because it showed promise in the lab, this does not necessarily mean it will work on humans.
The second problem with the experiment is that it looked at the effects of caffeine on testosterone, not dihydrotestosterone (DHT).
See, while testosterone is known to have some negative effects on hair follicles, it is the DHT metabolite which is the real cause of male pattern hair loss.
DHT binds to the hair follicles. Over time, this shrinks them until they eventually stop producing hair.
So while caffeine may have boosted growth in lab-grown hair follicles exposed to testosterone, it might have been completely ineffective if the hair follicles had been exposed to the far more potent DHT.
At best, this research supports further investigation into the effects of caffeine on androgenetic alopecia.
Might caffeine shampoo work for other hair loss conditions?
There are many different types of hair loss besides male pattern baldness. And evidence suggests caffeine shampoo may be beneficial for some of them.
For example, this study showed an impressive reduction in telogen (resting) hair after 3 months of treatment with caffeine liquid:
Normally, around 15% of your hair will be in the resting phase. The other 85% will be visible, growing, hair.
But with telogen effluvium, a much larger percentage of hair is in the resting phase, making hair look much thinner.
It’s a temporary condition that is self correcting. In time, hair returns to its normal growth cycle.
And this evidence suggests caffeine shampoo may help speed up the return to normal, encouraging telogen hair to enter the anagen stage more quickly. This would help sufferers of telogen effluvium recover more quickly.
What’s more, this effect might also be beneficial for another type of hair loss: involutional alopecia.
Involutional alopecia – natural hair thinning as a result of old age – is also caused by changes in the hair growth cycle.
As we get older, hair cycles naturally shorten. Hair stays in the growth stage for much less time before entering the rest stage. This makes hair appear thinner.
But if the study above is accurate, caffeine may reduce the effects of this.
In fact, one company – Plantur 39 – specifically markets a caffeine based shampoo at women over 40 for this reason. Longer anagen phase = thicker looking hair.
So, does caffeine shampoo work for hair loss?
If you’re simply looking to improve the volume of your hair, it might help somewhat. Evidence suggests caffeine has a positive effect on hair growth cycles, extending the anagen phase and reducing the telogen phase.
And for certain kinds of hair loss – those caused by changes in the normal growth cycle – this may indeed be beneficial.
But for androgenetic alopecia, more research is needed.
If you are suffering from male pattern baldness, it may initially improve the appearance of your hair slightly. But this might just be as a result of reduced telogen hair. This is only a temporary solution and doesn’t address the root cause: DHT.
And male pattern hair loss is far easier to prevent than reverse. Once you’ve lost your hair, it is very hard to grow it back.
So if you do decide to give caffeine shampoo a try, it is important to use hair loss products that address the hormonal cause of hair loss: DHT as well. By itself, caffeine shampoo won’t stop hair loss.