5 Side Effects Of Tulsi Or Holy Basil You Need To Know

Side effects of tulsi

“Elixir of life,” “liquid yoga,” ”Ayurveda’s golden remedy” …. tulsi or holy basil has some solid credentials thanks to its wide-ranging health benefits. The tulsi or holy basil plant is almost ubiquitous in Indian homes, revered in many Indian cultures, and generally has a good safety profile. But for all its goodness, it may be still out of bounds for some of us. Here are some potential side effects or health implications you should be aware of.

1. May Impact Fertility In Men And Women

Tulsi has been seen to have a negative effect on fertility in both genders. While this isn’t established yet in human studies and may apply to larger quantities in excess of dietary intake, there’s reason enough to play it safe if you are planning a family. Animal studies show that tulsi may lower sperm count and motility. It has also been found to decrease the weight of organs such as the testes, prostate, and adrenal glands which play a role in male reproductive health.1. There have also been reports about its ability to bring about changes in female reproductive organs such as the uterus and ovary.2


The antifertility effect of tulsi is thought to stem from its ability to modulate reproductive hormones. In fact, researchers are even studying its potential as a contraceptive agent.3 These antifertility effects may be reversible, though, and may not cause permanent damage – one animal study found that they were reversed a month after the test animals stopped feeding on tulsi leaves.4

2. May Not Be Safe During Pregnancy

A compound present in tulsi leaves known as estragol may cause uterine contractions. Therefore, it may be best to avoid this herb during pregnancy.5


3. May Interfere With Blood Thinning Medicines

Tulsi works as a blood thinner but this doesn’t typically cause harm. If you are, however, already on blood thinning medication, it can enhance its effects and cause problems with blood clotting. If you take blood thinners, do check in with your doctor before using tulsi. 6

4. May Add To The Effects Of Diabetic Medication

Various studies have found that tulsi can lower blood sugar. And if you take medication to control your blood sugar, it may enhance this effect and even cause levels to fall too low. Again, speak to your doctor before consuming tulsi if you are on medicines for diabetes.7


5. May Stain Your Teeth

Traditionally, in many Asian communities, tulsi leaves are supposed to be swallowed rather than chewed. They are considered sacred and chewing them is thought to be disrespectful. But there might be a scientific rationale for this too. Tulsi leaves contain iron and may, therefore, stain your teeth when chewed.8 This may not really affect your dental health but can cause discoloration. Instead of chewing them, you can simply gulp them down with some water.9