Picrorhiza kurroa

Picrorhiza kurroa is a herb from Ayurveda that is commonly called Kutki or Kutaki. It contains a 'bitter principle' which is a mixture of two molecules, the irioid glycosides known as picroside I and picroside II (picroside II also being called kutkoside) and the mixture overall is then called kutkin or picroliv. Overall, these are the active components.

The herb itself, due solely to the kutkin molecules, appears to be potently hepatoprotective (protective of the liver) when ingested prior to or taken after exposure to a toxin. The protective effects seem to extend to all tested toxins or stressors that are known to alter liver function, and appear to also extend to states of intrinsic liver dysfunction (viral hepatitis and NAFLD from a high fat diet). Most notably it is protective against Tylenol, alcohol, and the deathcap mushroom with a potency that is greater than silymarins (the active parts of milk thistle supplementation).

This fairly remarkable hepatoprotection from picrorhiza kurroa is limited by its lack of human studies, as despite the multitude of animal research on the topic there appears to only be one study in humans which showed that a very low dose of the supplement (25mg kutkin) was effective against viral hepatitis. Future studies in humans are needed to confirm its protective effects, and currently picrorhiza kurroa is a remarkably promising herb.

Supplementation of picroliv (picroside I plus picroside II) appears to be most effective in at 12mg/kg (the higher dose, 24mg/kg, is not significantly more effective than 12mg/kg in most cases) and this leads to a preliminary human dosage of:

• 130 mg for a 150lb person

• 170 mg for a 200lb person

• 220 mg for a 250lb person

Although the above dosage levels are ideal, lower doses also appear to be effective and the lone human study used a total picroside I and II dosage of around 25mg.

If using an extract of picrorhiza kurroa, then the above dosage refers to the total picroside I and II content (kutkin or picroliv) rather than the weight of the plant itself. For example, a plant extract that is 1,000 mg and contains 4% picroliv will confer 40 mg picroliv.

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what effects picrorhiza kurroa has on your body, and how strong these effects are.

Grade	Level of Evidence [show legend]
	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
	Symptoms of Vitiligo	Notable	- See study	The one study using picrorhiza kurroa for the purpose of treating vitiligo noted that after daily usage that 27% of the subjects experienced complete resolution of symptoms (curative effect)
	Bilirubin	Minor	- See study	Supplemental picrorhiza kurroa can reduce bilirubin in a model of acute viral hepatitis, although no comparisons to reference drugs have yet been made.
	Liver Enzymes	Minor	- See study	Supplementation of picrorhiza kurroa is able to reduce circulating liver enzymes in acute viral hepatitis. While animal research suggests it is more potent than Milk thistle, the human evidence is not yet able to directly compare the two.

Studies Excluded from Consideration

• Confounded with ginger and ginkgo biloba^[1]

• Confounded with other ayurvedic herbs^[2]