Onion and testosterone levels in males
What it found
Onion and onion extracts were linked to higher testosterone in male rats, and in one small study in men.
Most of the evidence comes from animal studies.
What they found
Studies in people
The one human study
One study in healthy men found that onion extracts raised testosterone. The authors say more studies in people are still needed.
Animal and lab studies
Testosterone in male rats
About 75% of the studies that directly tested onion and testosterone found a rise in testosterone in male rats. The other 25% found no clear effect, mostly in rats given cadmium or aluminum, which can permanently damage the reproductive organs.
Luteinizing hormone
In male rats, onion juice and watery onion extract raised levels of luteinizing hormone, the signal that tells the testes to make testosterone.
Antioxidant protection
Onion raised antioxidant enzymes in the testes of male rats and lowered a marker of oxidative damage. This may help Leydig cells, the cells that make testosterone, work better.
Blood sugar and insulin
Onion has been shown to lower blood sugar and reduce insulin resistance in diabetic rats. Diabetic rats given onion had higher testosterone than untreated rats.
Quercetin in onion
Onion ranks highest among 28 vegetables for quercetin. In male rats, quercetin raised testosterone after damage from arsenic, phthalates, atrazine, sulphasalazine or cadmium.
What the authors conclude
“Collectively, there is an evidence that onion or onion extracts (e.g., aqueous extract ~30 mg day −1 ) enhances testosterone production in males. However, this effect requires further approval in humans, mainly by conducting clinical trials.”
Also in their conclusions
- They say there is evidence that onion or onion extracts, such as about 30 mg a day of watery extract, raise testosterone production in males.
- They say this effect still needs to be confirmed in people, mainly through clinical trials.
- They describe the main ways onion may work: raising luteinizing hormone, fighting free radicals in the testes, boosting antioxidant defences, improving insulin resistance, increasing nitric oxide, and changing the activity of an energy-regulating enzyme.
How it was done
Testosterone is the main male sex hormone, and low levels are linked with diabetes, infertility, Alzheimer's, osteoporosis, depression and heart disease. The authors wanted to see whether a common food like onion could help maintain or raise it.
They searched three research databases for studies published from April 1967 to December 2018 that looked at onion and testosterone. Almost all the direct studies used male rats, given onion juice, watery onion extract or onion bulb by mouth for 10 to 60 days. Only one study was in healthy men.
What it can’t tell you
- Almost all the direct studies were in male rats, so they cannot show what happens in men.
- The single human study was small and needs confirming in larger trials.
- The studies used onion juice, extracts or bulb, not the amounts people typically eat.
Who paid
- Conflicts
- The author declares no conflict of interest.
- Authors work at
- Jordan University of Science and Technology, Jordan
The paper
- Title
- Testosterone in Males as Enhanced by Onion ( Allium Cepa L. )
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Cite
- Banihani SA (2019). Testosterone in Males as Enhanced by Onion ( Allium Cepa L. ). Biomolecules. doi:10.3390/biom9020075Free full textPubMed 30795630DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error