Researchers combined results from six studies involving 262 people to see if a special yeast product could help with weight loss. The yeast product, made from baker’s yeast (Saccharomyces cerevisiae), was processed into an active ingredient that people took as a supplement. Compared to people taking a fake pill, those taking the yeast product lost about 3 pounds more, had lower BMI scores, and lost more body fat. The results look promising because the supplement is safe, affordable, and available without a prescription. However, scientists say more long-term studies are needed to see if the benefits last over time.

The Quick Take

  • What they studied: Does a supplement made from baker’s yeast help people lose weight and body fat?
  • Who participated: 262 adults who were overweight or obese across six different research studies. All studies were high-quality trials where some people got the yeast supplement and others got a placebo (fake pill) without knowing which they received.
  • Key finding: People taking the yeast supplement lost an average of 3.08 pounds more than those taking the placebo. They also had lower BMI scores (a measure of weight relative to height) and lost about 1.93 kg more body fat. These differences were statistically significant, meaning they’re unlikely to have happened by chance.
  • What it means for you: If you’re trying to lose weight, this yeast supplement may provide modest additional help when combined with diet and exercise. The benefits appear real but not dramatic—think of it as a helpful tool, not a miracle cure. It’s safe and inexpensive, making it accessible to more people than expensive prescription weight-loss drugs.

The Research Details

This was a meta-analysis, which means researchers searched scientific databases for all high-quality studies on this topic and combined their results together. They looked for studies published between April and August 2025 in eight different databases, including PubMed and clinical trial registries. They only included studies that were randomized controlled trials—the gold standard in medical research where participants are randomly assigned to either get the real supplement or a placebo (fake pill), and neither the participants nor researchers knew who got which treatment.

The researchers carefully checked each study for quality problems using a tool called ROB-2 (Risk of Bias tool). They also used a system called GRADE to rate how confident they could be in the results. They followed strict guidelines from Cochrane and PRISMA, which are international standards for doing this type of research review.

By combining results from multiple studies, researchers can see the bigger picture instead of relying on just one study. This approach is more reliable because it reduces the chance that one study’s unusual results will mislead us. The fact that all included studies were randomized and placebo-controlled means the results are more trustworthy than studies without these features.

All six studies included in this analysis were rated as low risk of bias, which is excellent. This means the researchers did a good job conducting their studies and the results are likely accurate. However, there was some variation between studies in how much benefit people experienced (called heterogeneity), which slightly reduces our confidence in the exact numbers. The certainty of evidence was rated as ’low’ due to this variation, meaning while the results appear real, we should be somewhat cautious about the precise amounts.

What the Results Show

The yeast supplement produced measurable weight loss compared to placebo. On average, people taking the supplement lost 3.08 kg (about 6.8 pounds) more than those taking the fake pill. This difference was highly statistically significant (p < 0.001), meaning there’s less than a 0.1% chance this happened randomly.

Body Mass Index (BMI), which doctors use to assess whether weight is healthy for a person’s height, decreased by 0.87 kg/m² more in the supplement group. While this might sound small, it represents a meaningful improvement in health metrics.

Fat mass specifically decreased by 1.93 kg (about 4.2 pounds) more in the supplement group compared to placebo. This is important because losing fat (rather than muscle) is the goal of healthy weight loss. The reduction in waist circumference showed a trend toward improvement but didn’t quite reach statistical significance, though the difference was close (p = 0.06).

The consistency of results across studies was generally good for body weight (low variation between studies), suggesting this finding is reliable. However, there was more variation between studies for BMI and fat mass measurements, indicating that the supplement’s effects may differ somewhat depending on other factors like diet, exercise, or individual characteristics. No serious safety concerns were reported across any of the studies, suggesting the supplement is well-tolerated.

This is the first meta-analysis (combined analysis of multiple studies) on this specific yeast-derived supplement for weight loss, so it provides new evidence by bringing together previously scattered research. The weight loss amounts observed (about 3 kg) are modest compared to prescription weight-loss medications, but the supplement’s safety profile and low cost make it potentially valuable as a complementary approach, especially in countries where expensive medications aren’t accessible.

The total number of participants (262) is relatively small for drawing firm conclusions. The studies varied in their methods and measurements, which creates some uncertainty about the exact benefits. Most importantly, all studies were short-term, so we don’t know if the weight loss continues or if people regain the weight after stopping the supplement. The studies were also conducted in controlled settings, so real-world results might differ. Additionally, we don’t have detailed information about whether the supplement works better for certain types of people or in combination with specific diets or exercise programs.

The Bottom Line

The yeast supplement appears to provide modest weight loss benefits (about 3 pounds more than placebo) with good safety. It may be worth considering as part of a comprehensive weight management plan that includes healthy eating and exercise. Confidence level: Moderate (the evidence is real but not overwhelming). Start with the recommended dose and track your progress over 8-12 weeks to see if it works for you personally.

This supplement may be helpful for adults who are overweight or obese and want additional support for weight loss. It’s particularly relevant for people in lower-income countries where expensive prescription weight-loss drugs aren’t affordable or available. However, this supplement should not replace healthy eating and exercise—it works best as an addition to these lifestyle changes. People with yeast allergies should avoid it. Pregnant women, nursing mothers, and people with certain medical conditions should consult their doctor first.

Based on the studies reviewed, you might expect to see measurable weight loss within 8-12 weeks of consistent use. However, the studies didn’t track people long-term, so we don’t know if benefits continue beyond a few months or if weight returns after stopping the supplement. Plan to use it as part of a long-term lifestyle approach rather than expecting permanent results from the supplement alone.

Want to Apply This Research?

  • Log your daily supplement intake and weekly weight measurements. Also track waist circumference monthly and note any changes in how your clothes fit. This creates a complete picture of whether the supplement is working for your body specifically.
  • Set a daily reminder to take the supplement at the same time each day (such as with breakfast). Pair this with logging one healthy meal choice daily to reinforce that the supplement works best with good nutrition habits.
  • Track weight weekly (same day, same time), measure waist circumference monthly, and assess energy levels and appetite changes. After 12 weeks, review your data to decide if the supplement is providing noticeable benefits for you. If not seeing results, consult a healthcare provider about other options.

This research summary is for educational purposes only and should not replace professional medical advice. While this meta-analysis shows promising results, the supplement is not a substitute for healthy eating, regular exercise, and medical supervision. Before starting any new supplement, especially if you have existing health conditions, take medications, are pregnant, nursing, or have allergies, consult your healthcare provider. Results vary between individuals, and long-term safety and effectiveness have not been established. This supplement is not approved by the FDA for weight loss treatment. Always purchase supplements from reputable sources and discuss with your doctor how this supplement fits into your overall health plan.