Just when you thought you had a handle on all the trending beauty oils, a new contender emerges to challenge that. Enter bhringraj oil, the star ingredient in numerous highly-rated hair care products praised for stimulating hair growth—alongside a host of other benefits.

So, what is bhringraj oil exactly, and what makes it such a valuable ingredient in hair care? According to Jennifer Davis Alexander, Ph.D., a cosmetic scientist, holistic wellness expert, and founder of Dr. Jen Knows Skin, it’s derived from an herb known scientifically as Eclipta alba or Eclipta prostrata, which has been used in traditional medicine for what she terms “millennia.”

These herbs grow wild in tropical and subtropical climates, including West Africa, Brazil, India, and Thailand, says Dr. Alexander. She notes it’s so powerful because it’s “rich in phytonutrients and minerals, such as flavonoids, potassium, magnesium, and iron, all of which play an integral role in hair and scalp health.

Ahead, we break down everything you need to know about bhringraj oil for hair, including potential benefits, who should use it, and how to apply it.