Research review
Does papaya enzyme help with weight loss? What the research does and doesn't show
No human trial testing papain, papaya leaf extract or any papaya product for weight loss was found. A 2026 rat study on fruit-peel extract and a 2024 mouse study on leaf juice both found differences in body-weight and metabolic measures, but neither used papain, and neither was tested in people.
The evidence doesn't support papain, papaya leaf juice or any papaya-derived product as a weight-loss aid in people — no human trial was found testing any of them for that purpose. Two animal studies found body weight was different in papaya-treated groups compared with controls, using preparations and doses that don't translate into a capsule or tablet recommendation.
What the evidence doesn't support
It doesn't support papain — the enzyme sold in "papaya enzyme" tablets — papaya leaf extract, or any papaya fruit or seed preparation as something that makes a person lose weight; no controlled human trial testing any of these for weight loss was found. The animal research below shouldn't be read as a stand-in for that missing human evidence, and none of it tested a product like the ones sold as supplements.
What the trials found
A 2026 lab and animal study extracted the peel of ripe papaya fruit with methanol and tested it two ways: first against a digestive enzyme (pancreatic lipase) in a test tube, where the extract blocked the enzyme's activity in a dose-dependent way, and then in rats fed a high-fat diet for several weeks. By the end of the feeding study, body weight, cholesterol and triglyceride readings had all moved in a different direction in the extract-fed rats than in untreated rats on the same diet, and pancreas, liver and kidney tissue looked different under the microscope between the two groups. The study also included a fourth group of rats given orlistat, a prescription weight-loss drug, as a comparator; this page isn't the place to referee how the extract and the drug compared, only to note that the study used one. This is a fruit-peel extract, not papain, leaf extract, or any product typically sold as "papaya enzyme," tested in rats at a lab-derived dose, with no human trial of any kind.
A 2024 study gave older, high-fat-diet-fed mice a juice made from papaya leaves for 30 days, alongside a calorie-restricted diet. Compared with mice on the restricted diet alone, the papaya-leaf-juice group's body weight, blood sugar and cholesterol numbers moved further in the same direction over the study period. Because every mouse in this study was also on a restricted diet, the leaf juice's contribution can't be separated from the effect of the diet change itself, and again, this used a leaf preparation at a mouse-scaled dose, in mice, not a human trial of any papaya product.
Questions people ask
Does papaya enzyme make you lose weight?
No human trial testing papain, papaya leaf extract or any papaya product for weight loss was found. The two related findings are both animal studies, using a fruit-peel extract and a leaf juice — neither is the "papaya enzyme" sold as a digestive supplement, and neither has been tested in people.
Is papaya enzyme good for weight loss?
That's not established by any human research found for this review. See papaya enzyme benefits: what the research does and doesn't show for what has and hasn't been studied about papain more broadly.
Does papaya help burn fat?
No trial measured fat-burning directly in people from any papaya product. A lab test found a papaya fruit-peel extract blocked a fat-digesting enzyme in a test tube, a mechanism, not a demonstrated outcome in a person.
When to talk to a doctor
Weight management that involves a medical condition, a significant amount of weight, or a plan alongside medication is worth discussing with a doctor rather than working through with a supplement search — papaya enzyme products are not a treatment for obesity or a substitute for a doctor-guided plan. If you're taking a prescribed weight-management medication or have diabetes, talk to your doctor before adding any new supplement.
Related reading: papaya enzyme benefits: what the research does and doesn't show, does papaya enzyme help with a parasite cleanse or detox?, and how much papaya enzyme should you take a day.
Sources
- Phytochemical profiling and anti-obesity potential of the methanol extract of Carica papaya ripe fruit peel A 2026 rat study found a methanol extract of papaya fruit peel inhibited a fat-digesting enzyme in a test tube and was associated with differences in body weight, lipid markers and organ tissue appearance in rats on a high-fat diet compared with untreated rats on the same diet; the study also ran a group given the prescription drug orlistat as a comparator. This is fruit-peel extract, not papain, tested in rats, with no human trial.
- Supplementation of papaya leaf juice has beneficial effects on glucose homeostasis in high fat/high sugar-induced obese and prediabetic adult mice A 2024 study found older, diet-induced-obese mice given papaya leaf juice alongside a calorie-restricted diet for 30 days had lower body weight and blood sugar than the study reports for calorie restriction alone, but because every mouse was also calorie-restricted, the juice's own contribution can't be separated from the diet change, and this is a mouse study of leaf juice, not papain, with no human trial.
*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.