Kratom use is associated with modest weight loss, though the effect isn’t dramatic and isn’t consistent across all populations. A meta-analysis published in Frontiers in Pharmacology found that regular kratom users had a BMI roughly 1.5 points lower than non-users. That’s meaningful but not extreme, equivalent to perhaps 10 pounds for an average-height person. The picture is more complicated than a simple yes or no.
What the Research Shows About BMI
The most comprehensive look at kratom and body weight comes from a systematic review pooling data across multiple studies. Kratom users showed a statistically significant BMI reduction of about 1.5 kg/m² compared to healthy non-users. But the results varied sharply by population. Among Thai participants, the difference was larger: kratom users had BMIs about 2.1 points lower than non-users, with highly consistent results across studies. Among Malaysian participants, there was essentially no difference at all.
That geographic split likely reflects differences in how kratom is used, the specific preparations consumed, dietary patterns, and physical activity levels in each population. In Thailand, traditional kratom use often involves chewing fresh leaves or brewing tea, sometimes as part of manual labor. These contextual factors make it hard to isolate kratom itself as the cause of lower body weight. The people using kratom may simply live differently in ways that also affect their weight.
How Kratom Might Affect Weight
Kratom’s primary active compound interacts with opioid receptors in the body. These receptors play a role in regulating energy metabolism and how the body processes fats and sugars. The same compound also reduces the activity of an enzyme involved in inflammation and fat metabolism, which is linked to blood triglyceride levels. Together, these pathways could shift how the body stores and burns energy, though this has been studied more in animals than in humans.
At lower doses, kratom acts as a mild stimulant, which could theoretically increase energy expenditure or reduce the desire to eat. At higher doses, it has more sedating, opioid-like effects. This dual nature means the dose you take likely matters for whether kratom nudges your metabolism in one direction or another.
Appetite Suppression as a Side Effect
Loss of appetite is a recognized side effect of kratom, though it’s not one of the most common ones. In a survey of regular U.S. kratom users, decreased appetite was reported by less than 1% of respondents as a notable effect. However, users who took more than they intended, doses in the range of 8 to 9 grams of powder versus the 6 to 7 grams they considered effective, were more likely to report feeling unable to eat. As one respondent put it: “Too much kratom would make me feel agitated and anxious. I also wouldn’t be hungry.”
This suggests appetite suppression is more of an overdose-adjacent side effect than a reliable, dose-dependent property. It’s the kind of thing that happens when you take too much, not necessarily a predictable response at normal doses. That makes kratom a poor candidate for intentional appetite control.
Strain Type Doesn’t Seem to Matter
Kratom is sold in red, green, and white strains, each marketed with different supposed effects. Red strains are typically described as calming, white strains as energizing, and green strains as somewhere in between. Users do report different subjective experiences across strains when it comes to things like energy, focus, and sleepiness. But when researchers asked users to rank “to lose weight or to reduce appetite” as a motivation for use, there was no meaningful difference between strains. All three ranked it near the bottom of reasons for use, and the rankings were statistically identical. If one strain were notably better at suppressing appetite, it doesn’t show up in how people actually use them.
Risks That Outweigh the Weight Effect
Even if kratom contributes to a modest reduction in body weight, it carries risks that make it a poor choice as a weight management tool. The FDA has warned consumers against using kratom for any medical purpose, citing the potential for liver toxicity, seizures, and substance use disorder. There are no FDA-approved kratom products on the U.S. market, and kratom is not legally sold as a drug, dietary supplement, or food additive.
Substance use disorder is a particular concern. Documented cases show people using more kratom than intended, developing tolerance (needing more for the same effect), experiencing cravings, and going through withdrawal symptoms when they stop. Some kratom products have also been found contaminated with bacteria or heavy metals, adding unpredictable health risks on top of the drug’s own effects.
The modest BMI difference seen in studies, roughly 1.5 points, is the kind of change that’s easily achievable through small dietary adjustments or regular walking. Given that kratom’s weight effects are inconsistent across populations, likely tied to broader lifestyle factors, and accompanied by real safety concerns, pursuing weight loss through kratom use means accepting significant risk for an uncertain and small benefit.