While stinging nettle may sound like a dangerous plant, it has many health benefits. It can reduce inflammation, help reduce allergies, treat arthritis, and increase testosterone. Although it is considered safe, stinging nettles has its risks and side effects as well. Keep reading to learn some surprising benefits and risks of stinging nettle use.
What is Stinging Nettle?
Stinging nettle (Urtica dioica) is an herb native to parts of Europe, Africa, Asia, and North America. This unique plant has been used medicinally for its healing effects by the Ancient Greeks [R].
It is true that by touching the leaves of a wild stinging nettle can cause skin irritation. However, when processed for consumption, the nettle’s stinging hairs are crushed, cooked, or boiled in a way that eliminates their stinging abilities and makes them safe for consumption [R].
Stinging nettle contains many valuable vitamins and nutrients, including [R]:
It also contains other compounds responsible for its health and antioxidant effects [R]:
These anti-inflammatory effects appear to also help allergies, reduce nasal congestion, help with arthritis, and more.
Health Benefits of Stinging Nettle
1) Stinging Nettle Can Reduce Inflammation
In a study (RCT) of 37 arthritis patients, combining stinging nettle tea with diclofenac (an anti-inflammatory drug) enhanced the drug’s anti-inflammatory effects [R].
In mouse immune cells (macrophages), stinging nettle extract was as effective at reducing inflammation as a standard treatment (Celastrol). Both of them were powerful antioxidants and anti-inflammatory [R].
2) Stinging Nettle Helps Relieve Allergies
Taking stinging nettle supplements helps decrease allergies. Scientists believe this may be due to the plant’s ability to reduce histamine production and reduce inflammatory markers, but more research is needed to confirm this [R].
In one study, 57% of patients were said to have rated nettle as ‘effective’ in helping allergies, with 48% even saying nettle was more effective than allergy medications they had used previously [R].
3) Stinging Nettle May Increase Free Testosterone
Free testosterone is how much testosterone is in the blood that’s not in use at the time and bound to SHBG. The more testosterone that’s not bound to SHBG, the more free and usable testosterone there is available for the body. Testosterone that’s bound to SHBG is unusable to the body [R].
Stinging nettle contains a substance called 3,4-divanillyltetrahydrofuran, which binds to SHBG. Bodybuilders have traditionally used that substance to increase free testosterone [R].
So while nettle does not seem to increase total testosterone in the blood, it does appear to increase usable testosterone levels by binding to SHBG, making more testosterone available for use by the body [R, R].
There is also evidence that stinging nettle reduces the conversion of testosterone into estrogen, an effect that is increased by adding saw palmetto. It acts on the enzyme (aromatase) that converts testosterone to estrogen, but not on testosterone receptors [R].
4) Stinging Nettle Helps Relieve Arthritis and Pain Symptoms
Stinging nettle’s anti-inflammatory properties also help relieve arthritis symptoms. A combination of stinging nettle and the supplement devil’s claw significantly reduced symptoms of arthritis compared to placebo in a 12-week study (DB-RCT) of 92 arthritis patients [R].
Stinging nettle’s arthritis-relieving properties may be due to its ability to inhibit NF-kB activation [R].
Urtication, also known as ‘flogging with nettles,’ is a technique where users purposely apply stinging nettle to the body to generate inflammation. This has been used since Ancient Roman times as a treatment for chronic rheumatism [R].
There is also evidence that using stinging nettle topically can help relieve pain in those with:
5) Stinging Nettle May Help with Benign Prostatic Hyperplasia (BPH)
Benign Prostatic Hyperplasia (BPH) is when the prostate gland becomes enlarged (usually due to age), which causes difficulty urinating. Or, it can cause excessive urination (especially at night), frequent urination, sense of incomplete urination, an urge to urinate, and weak urinary stream. In some cases, it can also cause sexual dysfunction [R, R].
A review of several studies (RCTs) showed that stinging nettle extract is effective at improving the symptoms of an enlarged prostate, with a low risk of negative effects and toxicity [R].
In a study (DB-RCT) of 246 BPH patients, a special extract of stinging nettle was safe and effective in treating prostate enlargement when compared to placebo [R].
In another 6-month study (DB-RCT) of 558 people, stinging nettle was significantly better at improving the following [R]:
- Relief of lower urinary tract
- Maximum urinary flow rate
- Residual urine volume
- Prostate size
- International Prostate Symptom Score
Additionally, another study (DB-RCT) combined stinging nettle and saw palmetto extract. It was as effective as the prescription drug finasteride, which is used to treat enlarged prostates. It was also better tolerated [R].
6) Stinging Nettle May Decrease Blood Sugar
In a study (DB-RCT) of 92 subjects, stinging nettle extract lowered fasting blood sugar levels and other blood sugar levels when compared with the placebo [R].
7) Stinging Nettle Might Reduce Blood Pressure
Stinging nettle stems and leaves may lower blood pressure but could increase the risk of blood pressure dropping too low. In rats, stinging nettle acted on the kidneys to exhibit these effects [R].
8) Stinging Nettle as a Diuretic
Diuretics (or water pills) are medications designed to increase urine production. They can help remove excess sodium and water from the body. The leaves and stems specifically from the stinging nettle seem to increase urine flow and act as a diuretic [R, R].
- Treating high blood pressure
- Compensating for poor kidney function
- Reducing bloating
9) Stinging Nettle May Help Treat Burns
In rats, stinging nettle extract had a significant healing effect on second-degree burns. It was more effective than traditional methods (vaseline and silver sulfadiazine) [R].
Limitations and Caveats
Because most of this research was performed on animals, caution should always be used when applying research results to humans. Also, as with any supplement, care should be used in taking them.
For pregnant women, due to possible contractions of the uterus, stinging nettle may be unsafe to take during pregnancy. Contractions of the uterus can cause a miscarriage or cause women to go into early labor [R].
Although there is no evidence, stinging nettle may cause blood thinners (like Warfarin) to not work.
Forms of Supplementation
Stinging nettle is usually used in the following forms:
- Supplements (capsules and extracts)
- Tinctures (drugs dissolved in alcohol)
- Loose Leaves
If done with care and following instructions, wild stinging nettle can also be gathered and cooked into many recipes.
A dosage of 450 mg of stinging nettle extract is associated with beneficial effects for Benign Prostate Hyperplasia [R].
Increasing free testosterone is dose-dependent. Doses at 0.6 mg/ml helped inhibit testosterone binding to SHBG, and completely inhibited binding at 10 mg/ml [R].
Some people report increases in clarity, enhanced focus, and more vivid dreams.
People say that stinging nettle significantly helps with seasonal allergies. Some users have been taking it for over 10 years.
One user stated that it gave him stronger erections and loads of confidence by increasing free testosterone levels. However, there is only anecdotal evidence available regarding sexual function.
Other users praised stinging nettle for helping with hair growth, eczema, and gingivitis, but no clinical evidence is available for these benefits.
Some people claim to experience no health benefits at all from using stinging nettle supplements.