Does green tea help erectile dysfunction? There is no evidence that it does in men: no trial has tested green tea or its extracts in men with erectile dysfunction. The claims rest on rat studies of EGCG, one of the most abundant compounds in green tea, and in a large study of men's diets the flavonoid group green tea's catechins belong to showed no link with ED. As a drink it is harmless for most people; concentrated extracts carry a rare risk of liver harm.
Has green tea been tested for erectile dysfunction?
Only in animals. EGCG — "one of the most abundant and antioxidative ingredients isolated from green tea" — improved erectile pressure in aged rats given it by stomach tube for 12 weeks (Chen et al., 2017), protected sexual behaviour in diabetic rats (Huang et al., 2022) and prevented loss of erectile smooth muscle in young diabetic rats (Lombo et al., 2016). Not every result points one way: aged rats given green tea as their only drink for six months had lower androgen (male hormone) levels (Neves et al., 2008). A 2025 review of 26 such studies of EGCG and three other plant compounds found consistent improvements, but noted they relied on animal and laboratory models that "may not precisely reflect human physiological responses" (Geraldo et al., 2025).
The one human trial of a tea extract to measure sexual function gave a green-and-black tea blend to 46 men with urinary symptoms for 12 weeks. It reported a difference in sexual desire; it was not a trial in men with ED, and three of its authors were employed by Kemin Foods (Katz et al., 2014).
Do green tea's catechins protect the blood vessels that erections need?
Possibly for blood vessels in general, but no link with erections has been found. Green tea's catechins belong to the flavonoid group called flavan-3-ols (Braicu et al., 2013). A 2024 review of vascular trials found the clearest benefits for flavan-3-ols from cocoa, with green-tea catechins doing better in healthy people (Godos et al., 2024). But when 25,096 men were followed for 10 years, those eating the most flavan-3-ols were no less likely to develop ED; the flavonoids that did go with lower risk came from foods such as citrus, berries, apples and red wine (Cassidy et al., 2016). That diet evidence is set out in foods and erectile dysfunction.
Is green tea safe?
As a drink, for most people, yes; as a concentrated extract, there is a rare risk. The TGA says "the majority of C. sinensis use (including green tea in beverage form) is unlikely to cause harm", but "rare cases of harm to the liver have been associated with products that contain Camellia sinensis (green tea) extracts". About 267 listed medicines in Australia contain it, mostly as a concentrated extract and often for weight management; of 20 liver reports to the TGA, all but one involved concentrated extracts. Stop the product and see your doctor if you get nausea, stomach pain, pale stools, dark urine, itching all over, or yellow skin or eyes (TGA safety advisory, 2018).
Green tea also contains caffeine, which is found naturally in tea leaves. Healthy adults can safely have around 400 mg of caffeine a day, and if you have high blood pressure, caffeine can raise it (healthdirect).
Can you drink green tea with Viagra or Cialis?
Neither the Viagra nor the Cialis consumer medicine information names tea or caffeine; both ask you to tell your doctor or pharmacist about "vitamins or supplements that you buy without a prescription", which covers green tea extracts (Viagra CMI; Cialis CMI). The caffeine question is answered in caffeine with Viagra. One rat study found that caffeine-type compounds from green tea changed sildenafil levels (Radeva-Llieva et al., 2022); it has not been tested in people. The drink the Cialis label does single out is grapefruit juice — see grapefruit juice and Viagra.
What is the best drink for erectile dysfunction?
None works like a medicine. The best-studied drink, pomegranate juice, was tested in one trial and did not differ significantly from placebo (Forest et al., 2007); watermelon's citrulline was tested only as a supplement. Both are covered, with every other option, in what drinks work like Viagra.
What about ginseng tea?
Ginseng is a different plant with trials of its own. Red ginseng is the best-studied herb for erections, and a Cochrane review found a trivial effect on erectile-function scores (Lee et al., Cochrane 2021); see does ginseng help with erectile dysfunction?
The short answer
Drink green tea if you enjoy it, but not for your erections: the evidence is in rats, and a large study of men found no link between tea catechins and ED. Be wary of concentrated extracts, often sold for weight management. The natural and less invasive treatments with real evidence are weight loss, exercise, stopping smoking and pelvic-floor training, and if erection problems keep happening, a GP can look for the cause — ED is often the first sign of heart disease.
