Nettles is the common name for the herbal plant, Urtica dioica, also commonly called Stinging Nettle. Just knowing the name alone tells me that it could be a topical irritant and probably better used for treating alopecia areata. There are a lot of topical irritant type products/medicinal agents used to treat alopecia areata, and they are all very limited in effectiveness, but worthwhile trying. If you have alopecia areata, you know what I’m talking about.
The medicinal parts of Nettles are the fresh and dried flowering plant and roots. Nettle plants grow about 2-3 feet tall and have dark green leaves, where the flowers are covered with tiny stinging hairs. These stinging hairs contain an irritant that when in contact with human skin can cause irritation and possible allergic reactions.
Nettles has been used for years as a diuretic for those with enlarged prostates, benign prostatic hypertrophy (BPH). It’s also been used for asthma, arthritis, as an expectorant, astringent, and antispasmodic agent. Nettles has been used to treat kidney and urinary tract infections. Because of the topical irritant effect, applying extracts of Nettles to the scalp was “thought” to stimulate hair growth.
I have not seen any clinical study reports of the effectiveness for hair growth, whether it be in androgenetic alopecia (male pattern hair loss) or for alopecia areata.
The stinging reaction caused by the plant hairs is said to contain many active ingredients, such as formic acid, like what ant’s inject when they bite your skin and make you sting and burn, not to mention, itch. Other ingredients include: histamine, serotonin, acetylcholine, hydroxytryptamine and other irritants. So, many of these ingredients are neurotransmitters and affect nerve cells, so this is probably why it gives such an irritant effect, and why it may be better used for alopecia areata.
Other vitamin ingredients are Vitamins C and E, along with minerals, and rich in chlorophyll when eating the cooked nettle shoots.
Researchers, such as R. Hartmann, et al (1) demonstrated that extracts of nettle root and another herbal agent, pygeum (in the next article), partially block 2 enzymes, 5a-reductase, which makes dihydrotestosterone (DHT) and aromatase enzyme, which makes estrogens. Their studies showed that both root extracts were more effective in inhibiting these 2 enzymes, than either one alone. The nettles root extract was reported as effective only at high concentrations, while the pygeum was better at lower doses. The combination product, Prostatonin, has been used to treat BPH. It is hard to interpret “effectiveness” and how the studies were conducted.
Theme: “Oh no, another BPH product thought to grow hair.” How many times have you heard of prostate affecting agents being used to grow hair? Studies were done for BPH by researchers JJ Lichius and colleagues (1) where a reduction in prostate growth in mice occurred with high doses of nettle root extract. Other studies using other combinations, such as saw palmetto berries and nettle root extracts were used to treat BPH patients and found an inhibition of testosterone and estrogen. It is also thought that nettles is effective in blocking testosterone binding to sex hormone-binding globulin, which is a carrier protein that binds testosterone and limits its bioavailability in the body. Hence, nettles may help to maintain testosterone levels, and has been called an aphrodisiac.
Again, it is difficult to review the work that has been done, and how the results and studies were conducted and interpreted.
Theme: It seems that Nettles is best used in combination with another herbal agent, rather than alone.
Side Effects: Irritation, allergic reaction when used topically, in contact with skin. Consuming nettles can cause stomach upset and burning, as well as difficult urination and bloating, hence, edema. It should not be used when someone has heart or kidney problems, due to the fluid retention properties.
Dosage: Taken in oral forms such as tea mixtures, or advertised as “blood purifying teas”, it is also available for external application as an astringent. The average daily dose is 8 to 12 grams of drug, along with ample fluid intake of 2 liters a day (2). Doses for hair growth are typically 500 mg a day.
My opinion: It’s another one of those supposed “Works for BPH, and is thought to inhibit 5a-reductase, which makes DHT, which causes hair loss, which is sort of what Propecia does” type claims. Do you realize how many of these types of herbs and products exist? It seems like thousands, and I rarely ever see biochemical data showing the actual numbers of how well it inhibits DHT, so it can adequately be compared to treatments that actually work for hair loss.
If you can’t get finasteride (Propecia), or if you’ve had problems with finasteride, then nettles sounds like something you could try with “caution”. Again, I was not able to find controlled clinical studies showing its use in hair growth.
As stated above, make sure you have no other heart or kidney problems, as well as stomach/GI problems. If you do take it on a trial basis, be careful of any allergic reactions. If you are prone to being “allergic-sensitive” type person, then do be careful in taking only the smallest dose and increase gradually. Remember, it also has fluid retaining properties, so make sure your ankles don’t get puffy.
I wouldn’t expect it to do any more than finasteride, as it sounds like it may only be a weak 5a-reductase inhibitor, and the other concern is that it inhibits aromatase, which increases estrogens. We aren’t sure what specific role aromatase has, whether it is “good” or “bad” in hair growth, so again, “caution” is the word on nettles.
I don’t want to be negative on all herbal, medicinal agents, but again, caution should be used since no clinical data is listed to support nettles use for hair growth.