Quick Navigation

Holy Basil

A traditional anti-fertility agent and libido enhancer in Ayurveda, Holy Basil (also known as Tulsi) is currently being investigated for these two claims and its general health properties. A good source of dietary Ursolic acid, which may cause the anti-fertility aspects.

Our evidence-based analysis on holy basil features 26 unique references to scientific papers.

Research analysis led by .
Reviewed by
Examine.com Team
Last Updated:

Summary of Holy Basil

Primary information, health benefits, side effects, usage, and other important details

Holy Basil (also known as Tulsi, or Ocimum sanctum) is an ayurvetic herb which has historically been used to treat a variety of general ailments. It recently has been shown to hold scientific worth in the areas of liver protection and general anti-oxidant activity, as well as being classified as an adaptogen (reducing the effects of stress on the body).

It is also used as a Testosterone Booster, although no direct evidence exists in humans for this. It has also been demonstrated to hinder reproductive capacity.

Guidance from the experts

Learn what supplements to take for your specific health goals with the Examine Supplement Guides.

Want a deeper look at the research? Examine Members get full access to the comprehensive research database, monthly study summaries, and the latest in-depth analysis.

Your support allows us to be 100% independent and unbiased.


How to Take

Recommended dosage, active amounts, other details

500mg of the leaf extract taken twice daily appears to be recommended for neurological and adaptogenic effects of holy Basil, whereas the only evidence on other health effects or testosterone boosting are done in rats with the dosages of 100-200mg/kg and 500mg/kg respectively. This leads to an estimated human dose of:

  • 1,100-2,200mg for a 150lb person for general health and 5,500mg for testosterone boosting

  • 1,500-2,900mg for a 200lb person for general health and 7,300mg for testosterone boosting

  • 1,800-3,600mg for a 250lb person for general health and 9,100mg for testosterone boosting

These are estimated human dosages based on animal research, and it is unsure if they are the optimal doses for humans.

Easily stay on top of the latest nutrition research

Become an Examine Member to get access to the latest research. Get 150+ studies summarized for you across 25 different categories every month.

Members also have access to the Examine Study Database of 400+ supplements and their effects on 600+ health outcomes, as well as in-depth research analyses. Understand the whole body of nutrition and supplement evidence at a glance.

Get instant access — start your free 14-day trial

Already a Member? Click here to log in.


Human Effect Matrix

Unlocked for Examine Members

Easily stay on top of the latest nutrition research

Become an Examine Member to get access to the latest research. Get 150+ studies summarized for you across 25 different categories every month.

Members also have access to the Examine Study Database of 400+ supplements and their effects on 600+ health outcomes, as well as in-depth research analyses. Understand the whole body of nutrition and supplement evidence at a glance.

Get instant access — start your free 14-day trial

Already a Member? Click here to log in.


The Human Effect Matrix summarizes human studies to tell you what effects Holy Basil has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine Members. Not a Member? Try Examine Membership completely free for two weeks.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
Notes
grade-c Minor - See study
Appears to induce proliferation of T cytokines and T lymphocytes
grade-c Minor - See study
An increased level of NK cell count has been noted following ingestion of Tulsi leaves
grade-d Minor - See study
A decrease has been noted, but the studies are not overly robust at this moment in time
grade-d Minor - See study
May reduce blood glucose, with the potency demonstrated (fairly good) limited by the quality of the evidence currently
grade-d Minor - See study
A decrease in depressive symptoms during generalized anxiety disorder has been noted

Stay on top of the latest research

To unlock the full archives of our Study Database and research analyses, become an Examine Member today.

Start your 14-day free trial

Things to Note

Primary Function:

Also Known As

Ocimum sanctum, Green Tulsi, Sacred Basil, Tulsi, Ocimum tenuiflorum

Do Not Confuse With

Thai Basil (a table spice)

Goes Well With

Caution Notice

High doses of holy basil may be anti-fertility in males due to impairing spermatogenesis.

  • Many studies not using an ethanol-extract, suggesting the active ingredients may be fat-soluble in nature

  • Probably one of the only testosterone boosting compounds (whether it works or not) that hinders spermatogenesis, possibly related to the ursolic acid content

Get our free 5-day course on the essentials of supplementation.

At Examine, our incentives line up with yours — getting unbiased information. That's why we don’t sell any advertising or supplements.

Join over 250,000 people who have learned about effective versus overrated supplements, tips for buying supplements, and how to combine supplements for safety and efficacy.

Click here to see all 26 references.