Nettle tea: the trials used capsules and extracts, not the tea

By a meta-analysis of 8 randomized trials in 401 adults with type 2 diabetes, nettle supplements and extracts lowered fasting blood sugar by 18.01 mg/dl (95% CI -30.04 to -5.97). The trials disagreed sharply among themselves (I2 94.6%), and two of the eight were rated low quality. None of them used tea. In the US, supplements do not go through FDA approval the way medicines do, so anyone who takes medication, is pregnant or has a chronic illness should talk to a doctor before taking one. That includes anyone on medicine for diabetes, because we have no data on how nettle and those drugs combine. The same analysis found no significant change in HbA1c (-0.77%, 95% CI -1.77 to 0.22) or in insulin resistance. So whether nettle moves long-term diabetes control stays open, because the intervals are wide and the eight trials pulled in different directions. The joint trials tested mixtures. In 81 people with knee or hip osteoarthritis, a supplement of fish oil, vitamin E and nettle left them using 6.5 paracetamol-equivalent tablets a week against 16.5 on placebo after 3 months, and nettle's own share was never separated out. In 92 people with knee arthritis, a daily 2.7 tbsp (40 mL) drink of rosehip, nettle leaf, devil's claw and vitamin D improved the WOMAC pain score by 29.87 points against 10.23 on placebo over 12 weeks, in a trial of a sponsored product. In 2025 the German rheumatology society judged that none of the herbal preparations it reviewed, nettle included, works well enough to justify use in inflammatory joint disease. That verdict was about inflammatory joint disease only.

What a real portion looks like

• The EU herbal monograph sets nettle tea at 1.5 g of cut herb in 5.1 fl oz (150 ml) of boiling water, 3 to 4 times a day, for minor urinary complaints. — Adults and elderly Evidence E source
  Single dose 1.5 g in 5.1 fl oz (150 ml), daily dose 4.5 to 6 g

What it does to your health

• In a 6 month single-blind randomized trial of 120 people with pattern hair loss or shedding, a six-herb shampoo and lotion containing nettle reduced hair loss more than placebo. — 120 subjects with androgenetic alopecia and telogen effluvium, topical shampoo and solution for 6 months (n = 120) Evidence B source
  Less hair loss than placebo at every assessment point; size of effect not checked (full text not read)
• By a meta-analysis of 8 randomized trials in 401 people with type 2 diabetes, nettle supplements lowered fasting blood sugar by 18 mg/dl. — 401 adults with type 2 diabetes in 8 RCTs of nettle supplementation (n = 401) Evidence A source
  Fasting blood sugar -18.01 mg/dl (95% CI -30.04 to -5.97), I2 94.6%
• In an RCT of 81 people with knee or hip osteoarthritis, a supplement of fish oil, vitamin E and nettle cut painkiller use by 10 tablets a week over 3 months. — 81 patients with knee or hip osteoarthritis using NSAIDs or analgesics, 3 months (n = 81) Evidence B source
  Analgesics 6.5 vs 16.5 paracetamol-equivalent tablets per week, difference -10.0 (95% CI -4.9 to -15.1)
• In a 12 week RCT of 92 people with knee arthritis, a rosehip, nettle leaf and devil's claw drink improved the WOMAC pain score by 29.87 points against 10.23 on placebo. — 92 patients with gonarthritis drinking 2.7 tbsp (40 mL) of MA212 or placebo daily for 12 weeks (n = 92) Evidence B source
  WOMAC pain change 29.87 vs 10.23 points

Safety, limits and interactions

• The EU monograph lists nausea, vomiting and diarrhea as side effects of nettle herb, with unknown frequency. — users of nettle herb preparations Evidence E source
  Nausea, vomiting and diarrhea; frequency not known
• A 57 year old woman developed atropine poisoning after drinking nettle tea that turned out to be contaminated with deadly nightshade. — One 57 year old woman (n = 1) Evidence D source
  Atropine poisoning from tea contaminated with Atropa belladonna

What people believe that the data does not support

• The EU herbal monograph lists traditional uses of nettle herb for minor urinary complaints, minor joint pain and oily, seborrhoeic skin, and hair loss is not among them. — adults and adolescents Evidence E source
  Three traditional indications; no hair indication
• According to the German rheumatology society in 2025, no herbal preparation it reviewed, stinging nettle included, works well enough to justify use in inflammatory joint disease. — Patients with rheumatic diseases Evidence E source
  No preparation justified for inflammatory joint disease

Who this works differently for

• The EU monograph does not recommend nettle herb in pregnancy or breastfeeding, because its safety there has not been established. — pregnant and breastfeeding women Evidence E source
  Use not recommended
• The EU monograph advises against nettle herb for people told to limit their fluid intake, such as some heart or kidney patients. — patients with conditions where reduced fluid intake is advised Evidence E source
  Not recommended
• In a case report, a 30 year old woman taking a 500 mg stinging nettle supplement developed breast milk discharge that cleared a week after stopping it. — one 30 year old woman taking stinging nettle 500 mg for a month (n = 1) Evidence D source
  Galactorrhea resolved one week after discontinuation
• In a case report, a 30 year old woman taking a 500 mg stinging nettle supplement developed breast milk discharge that cleared a week after stopping it. — One 30 year old woman taking stinging nettle 500 mg for a month (n = 1) Evidence D source
  Galactorrhea resolved one week after discontinuation
• In a survey of 120 families of children with cancer, stinging nettle was the most used herbal product, taken by 43.2% of those using complementary medicine. — Families of 120 children with cancer aged 0 to 18 (n = 120) Evidence C source
  Stinging nettle 43.2% among CAM users
• The EU monograph does not recommend nettle herb during pregnancy or breastfeeding because safety has not been established. — Pregnant and breastfeeding women Evidence E source
  Use not recommended

What is still unknown

• A 2025 systematic review of 16 randomized trials of herbal hair loss remedies found only one trial that used nettle, a scalp shampoo and lotion mixing six herbs, not a tea. — 120 subjects (60 males, 60 females) with androgenetic alopecia (54) or telogen effluvium (66) (n = 16 RCTs in the review; 120 in the nettle-containing trial) Evidence A source
  No trial of nettle tea or oral nettle; nettle (Urtica urens leaf, Urtica dioica root) only as part of a topical six-herb formula
• A 2025 network meta-analysis of 19 randomized trials of oral supplements for pattern hair loss, in 1,658 patients, included no nettle product among the 16 supplements it compared. — patients with androgenetic alopecia in RCTs of dietary supplements (n = 19 RCTs, 1658) Evidence A source
  Nettle not among the supplements compared (full text searched for nettle and Urtica)
• Computer modeling suggests some compounds found in nettle, saw palmetto and fenugreek may bind 5-alpha reductase, the enzyme behind pattern hair loss, but this was never tested on hair in people. — in silico docking and molecular dynamics, no cells, animals or humans Evidence D source
  6 phytochemicals (incl. chlorogenic acid, rutin, ursolic acid) predicted to bind 5-alpha reductase
• The same meta-analysis found no significant change in HbA1c (-0.77%) or insulin resistance, so a lasting effect on diabetes control is unproven. — Adults with type 2 diabetes in 8 RCTs (n = 401) Evidence A source
  HbA1c -0.77% (95% CI -1.77 to 0.22), HOMA-IR -0.22 (-0.83 to 0.40), both not significant
• Laboratory data suggest a methanol extract of nettle reduced kidney stone crystals in rats, but no human trial of nettle tea for stones was found. — Rats with ethylene glycol induced kidney stones Evidence D source
  Less hyperoxaluria and crystalluria with nettle extract
• Nettle herb has never been tested for reproductive toxicity, genotoxicity or cancer risk, the EU monograph notes. — — Evidence E source
  No preclinical safety tests

The bottom line

The tea itself has a traditional recipe rather than a tested dose. The EU herbal monograph sets it at 1.5 g of cut herb in 5.1 fl oz (150 ml) of boiling water, 3 to 4 times a day, for minor urinary complaints, on the basis of long use and without proof that it works. It is written for adults and older people. That is a traditional recipe, not a dose tested in trials, and we have no card on how long it may be taken or on its use in children. For kidney stones there is only an animal result: a methanol extract of nettle reduced crystals in the urine of rats with induced stones. We found no human trial of nettle tea for stones. The EU monograph does not recommend nettle herb during pregnancy or breastfeeding, because its safety there has not been established. That is an absence of data, and no harm has been shown. In one case report a 30 year old woman taking a 500 mg nettle supplement for a month developed breast milk discharge that cleared a week after she stopped, while she was also taking echinacea and had a contraceptive implant. In another, from 1980, a 57 year old woman got atropine poisoning from nettle tea that turned out to be contaminated with deadly nightshade, so the harm came from the contaminant. Nettle herb has never been tested for reproductive toxicity, genotoxicity or cancer risk, the monograph notes. We have no card on how nettle interacts with medicines, so anyone taking medication, including for diabetes or blood pressure, should ask a doctor before taking a nettle supplement or extract. In a survey of 120 families of children with cancer, stinging nettle was the most used herbal product, taken by 43.2 percent of those using complementary medicine. The survey describes use and measured no effect, and five year survival did not differ. If a child is being treated for cancer, nettle is a question for the team treating them.

Sources

1. nttl-daily-r4-10 · herbal monograph
   SD=1.5 g of the comminuted herbal substance in 150 ml of boiling water as infusion, 3-4 times daily
   EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 · checked 2026-09-29
2. ev-nthl-02 · RCT
   Herbal formulations were found to be more effective in preventing and reducing hair loss than placebo at every assessment point.
   Acta Dermatovenerologica Alpina, Pannonica et Adriatica, 2018, 27(2):51-57 (Pekmezci et al.) · checked 2026-10-07
3. nttl-daily-r4-01 · meta-analysis of RCTs
   The results of the meta-analysis revealed a significant reduction in FBS concentrations (weighted mean difference [WMD]: -18.01 mg/dl, 95% confidence interval [CI]: -30.04 to -5.97, p < .001, I2 = 94.6%) following nettle supplementation.
   Phytother Res, 2020 · checked 2026-09-29
4. nttl-daily-r4-03 · RCT
   After three months of treatment, the mean use of analgesics in the active arm (6.5 PET/week) vs. the placebo arm (16.5) was significantly different (P < 0.001) with a group mean difference of -10.0 (95% CI: -4.9 to -15.1).
   Arthritis Res Ther, 2009 · checked 2026-09-29
5. nttl-daily-r4-04 · RCT
   The mean pre-post change of the WOMAC pain score (primary endpoint) was 29.87 in the MA212 group and 10.23 in the placebo group.
   Planta Med, 2017 · checked 2026-09-29
6. ev-nthl-08 · herbal monograph
   Gastrointestinal disorders: nausea, vomiting and diarrhoea. The frequency is not known.
   EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 (EMA/HMPC/261302/2022) · checked 2026-10-07
7. nttl-daily-r4-06 · case report
   The analyses of the tea specimen proved bad defilements among other things with elements of the "belladonna" (Atropa belladonna).
   Fortschr Med, 1980 · checked 2026-09-29
8. ev-nthl-05 · herbal monograph
   Traditional herbal medicinal product used in seborrhoeic skin conditions.
   EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 (EMA/HMPC/261302/2022) · checked 2026-10-07
9. nttl-daily-r4-05 · guideline
   None of the preparations investigated has a therapeutic efficacy that justifies its use in inflammatory joint diseases.
   Z Rheumatol, 2025 · checked 2026-09-29
10. ev-nthl-06 · herbal monograph
    Safety during pregnancy and lactation has not been established. In the absence of sufficient data, the use during pregnancy and lactation is not recommended.
    EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 (EMA/HMPC/261302/2022) · checked 2026-10-07
11. ev-nthl-07 · herbal monograph
    Because adequate fluid intake is required during treatment, Urtica dioica L. and Urtica urens L., herba are not recommended for patients with conditions where reduced fluid intake is advised.
    EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 (EMA/HMPC/261302/2022) · checked 2026-10-07
12. ev-nthl-09 · case report
    One week after discontinuation, she returned to the clinic with complete resolution of the galactorrhea.
    Am J Case Rep, 2021 · checked 2026-10-07
13. nttl-daily-r4-07 · case report
    One week after discontinuation, she returned to the clinic with complete resolution of the galactorrhea.
    Am J Case Rep, 2021 · checked 2026-09-29
14. nttl-daily-r4-08 · survey
    The most commonly used dietary supplement or herbal product was honey (43.2%) or stinging nettle (43.2%), respectively.
    Pediatr Hematol Oncol, 2012 · checked 2026-09-29
15. nttl-daily-r4-11 · herbal monograph
    Safety during pregnancy and lactation has not been established. In the absence of sufficient data, the use during pregnancy and lactation is not recommended.
    EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 · checked 2026-09-29
16. ev-nthl-01 · systematic review
    This trial evaluated the efficacy of applying a proprietary herbal shampoo and solution containing six different herbal extracts (Urtica urens leaf extract, Urtica dioica root extract, Matricaria chamomilla flower extract, Achillea millefolium aerial part extract, Ceratonia siliqua fruit extract, Equisetum arvense leaf extract) in 120 subjects (60 males, 60 females) with AGA (54) or TE (66).
    Naunyn-Schmiedeberg's Archives of Pharmacology, 2025, 398(12):16311-16354 (Allam et al.) · checked 2026-10-07
17. ev-nthl-03 · meta-analysis
    A total of 19 RCTs involving 1,658 AGA patients were included, with 894 patients in the supplement group and 764 in the control group.
    Front Nutr, 2025 · checked 2026-10-07
18. ev-nthl-04 · in silico study
    We found that 6 molecules-Jamogenin, Neodiosgenin, Chlorogenic acid, Rutin, Riboflavin, and Ursolic acid-are effective in binding to 5-AR.
    Frontiers in Bioinformatics, 2025, 5:1570101 (Hasannejad-Asl et al.) · checked 2026-10-07
19. nttl-daily-r4-02 · meta-analysis of RCTs
    However, no significant reduction was observed in insulin levels (WMD: 0.83 Hedges' g, 95% CI: -0.26 to 1.92, p = .13, I2 = 89.4%), homeostasis model assessment-estimated insulin resistance index (WMD: -0.22, 95% CI: -0.83 to 0.40, p = .49, I2 = 69.2%), or glycosylated hemoglobin percentage (WMD: -0.77%, 95% CI: -1.77 to 0.22, p = .12, I2 = 83.0%).
    Phytother Res, 2020 · checked 2026-09-29
20. nttl-daily-r4-09 · animal study via review
    This extract potentially dissolved the lithiasis and overcame the hyperoxaluria and crystalluria induced by ethylene glycol [31].
    Int J Mol Sci, 2018 · checked 2026-09-29
21. nttl-daily-r4-12 · herbal monograph
    Tests on reproductive toxicity, genotoxicity and carcinogenicity have not been performed.
    EMA/HMPC, European Union herbal monograph on Urtica dioica L.; Urtica urens L., herba, Final Revision 1, 2025 · checked 2026-09-29