Shaun Ward MSc ANutr
Nettle leaf is another term for stinging nettles, also called urtica dioica, from the Urticaceae family.
Most people know it as the plant that will sting you if your skin comes into contact with it, as the leaves have hair-like structures that produce serious itching and swelling.
However, what is less well-known is that the leaves have been a staple in herbal medicine since ancient times.
Nettle leaf extracts represent a processed supplement version of nettle leaf, where the leaves are dried and cooked so they can be safely consumed.
Its main uses are to promote male health, such as prostate health, urinary tract function, and hair growth, although females have been reported to take it to promote lactation and prevent uterine bleeding after childbirth.
The research behind nettle leaf is scarce, however the active ingredient is thought to be a molecule called beta-sitosterol.
There is currently no recommended dosage for nettle leaf extract from any reliable source.
If you are going to use this supplement, it would be wise to start with 300mg per day as this does result in side effects within the current human studies.
The Potential Benefits of Nettle Leaf Extract
Below is a list of every potential benefit that's got credible scientific backing:
It May Help To Reduce Inflammation
In animal and lab studies, nettle leaf extract taken orally can reduce the amounts of many inflammatory hormones .
Nettle leaf extract supplementation has shown to help osteoarthritis, but only when consumed with fish oil which leads to skepticism about the isolated effects of nettle leaf .
However, there does seem to be a decrease in some pro-inflammatory molecules such as IL-6 when administered orally to diabetics .
Yet researchers believe that the benefits of the leaves may only occur when applied as a topical cream to areas of the skin with severe inflammation .
For example, applying a nettle leaf cream onto arthritic areas has shown to significantly reduce the pain experienced by an individual .
Based on the current evidence, nettle leaf possesses anti-inflammatory properties, but the amount of current human trials is severely lacking to know the clinical relevance.
It May Help Improve Prostate Health
An enlarged prostate is known as benign prostatic hyperplasia, which is most common in elderly individuals when prostate health may begin to deteriorate.
360mg of nettle leaf supplementation per day has shown in a large clinical trial to reduce urinary complications (reduced flow rate) associated with this medical issue .
Smaller human studies have also noted long-term benefits in the follow-up period years after the initial trials ended .
Animal studies suggest the alleviation of decreased urinary rate is due to the beta-sitosterol content , although other compounds such as campesterol, sigmasterol and stimast-4-en-3-one may also be active ingredients by inhibiting the sodium/potassium pump .
Significant effects may be due to the inhibition of 5a-reductase, preventing the conversion of testosterone to DHT, which allows the size of the prostate to be reduced .
It May Help Lower Blood Pressure
Traditionally, nettle leaf has been used for the treatment of high blood pressure.
Certain extracts and fractions of nettle leaf do appear to possess antihypertensive activity, such as influencing nitric oxide metabolism to upregulate vasodilation .
In animal studies, it seems that an increase in the cardiovascular systems antioxidant defense is why the animals experience lower blood pressure levels from supplementation .
The effects on blood pressure in humans are still unclear, and additional human studies are needed before any recommendations can be made.
Nettle Leaf Extract Safety And Side Effects
The amount of oral nettle leaf needed to cause toxicity is extremely high, estimated to be around ~1.5 grams per kg bodyweight .
For the most part, consuming dried or cooked nettle leaf is regarded as generally safe, and no serious safety concerns are associated with its consumption in this form.
However, it is best for pregnant women to avoid consuming nettle leaf as it may trigger uterine contractions and increase the risk of a miscarriage .
It also goes without saying that people should be careful when handling fresh stinging nettle leaves, as this can cause serious rashes and itchiness.
Nettle leaf extracts represent a processed supplement version of nettle leaf, which is another term for stinging nettles.
This supplement may be beneficial for lowering inflammation (when taken orally or topically), improving prostate health, and lowering blood pressure.
Nettle leaf extract is regarded as a safe supplement to consume, and it is recommended to start at 300mg per day – although the best dosage has not yet been determined.