Does papaya enzyme help with kidney disease? What the research does and doesn't show

The evidence doesn't support papain, papaya leaf extract or papaya seed products as a way to protect or treat the kidneys or liver in people — no human trial was found. Several rat studies found kidney or liver tissue looked different, on lab measures and under the microscope, when animals given a papaya seed or leaf preparation were also exposed to a toxic dose of a drug or chemical, compared with animals exposed to the same toxin alone.

What the evidence doesn't support

It doesn't support papain, papaya leaf extract or papaya seed products as protective or restorative for kidney disease or liver disease in a person — no controlled human trial testing any papaya preparation in people with a kidney or liver condition was found. The animal studies below are about laboratory toxin-injury models, not a general "detox" or organ-support effect, and none of them tested papain, the digestive-enzyme product sold as "papaya enzyme."

What the trials found

Most of papaya's kidney and liver research comes from a specific type of study: give rats a drug or chemical known to damage that organ, and see whether a papaya seed or leaf extract, given before or alongside it, changes the outcome. A 2024 study gave rats gentamicin, an antibiotic with a well-known kidney-damaging side effect, and compared kidney-function blood markers and tissue samples in rats also given an ethanol extract of papaya seeds against rats given gentamicin alone; the study also ran a group given silymarin, a milk-thistle compound used as a reference antioxidant, as a comparator. An earlier 2018 study used the same gentamicin-injury design with papaya leaf extract instead of seed extract, tracking both standard and newer kidney-injury markers, and found the leaf-extract groups' markers moved in a different direction than the untreated-injury group's, in proportion to the dose given.

On the liver side, a 2021 study used carbon tetrachloride, an industrial chemical that reliably damages liver tissue in animal research, to injure rats' livers, then gave some of them a water extract of papaya seeds before, during or after the exposure. Oxidative-stress and inflammation markers, and liver-tissue appearance under the microscope, differed between the seed-extract groups and the untreated-injury group over the following weeks.

Every study here used a seed or leaf extract, not papain; used rats deliberately poisoned with a specific drug or chemical, not a person with a kidney or liver diagnosis; and used doses set for a rat's body weight in a lab, with no established human equivalent. None of it tests what a papaya supplement does for a person's existing kidney or liver condition, or for general "detox" of either organ in someone who hasn't been exposed to gentamicin or carbon tetrachloride.

Questions people ask

Does papaya enzyme help with kidney disease?

No human trial testing papain, papaya leaf extract or papaya seed products in people with kidney disease was found. The related animal research used seed or leaf extract, not papain, in rats given a kidney-damaging drug, which doesn't answer this question for a person with an existing kidney condition. Who should not take papaya enzyme covers the same gap for people specifically asking about kidney problems and papaya enzyme safety.

Is papaya good for the liver?

Most searches using "papaya" and "liver" together are really asking about kidney disease, based on how people search — but if you're specifically asking about the liver: a handful of rat studies found seed-extract-treated rats had different liver-tissue and blood-marker outcomes than untreated rats after a toxic chemical exposure. No human trial has tested papain, leaf extract or seed products for liver health or disease.

Can papaya enzyme cause kidney or liver damage?

No case report or trial in this research found papain, at a typical oral supplement amount, causing kidney or liver injury. The studies above tested papaya-derived extracts as a possible counter to damage from a separate, deliberately administered toxin — they don't suggest papaya itself is harmful to either organ, but they also don't establish it as protective in a person.

When to talk to a doctor

Kidney and liver conditions need medical diagnosis and monitoring, and papaya enzyme products are not a treatment for either. If you have a diagnosed kidney or liver condition, ask your doctor before adding papain, papaya leaf extract or papaya seed products, since none of the research above tested a person in that situation.

Related reading: who should not take papaya enzyme, does papaya enzyme help with a parasite cleanse or detox?, and papaya enzyme: what the research does and doesn't show.