Berberine vs. Metformin: The Pilot Trial Behind HbA1c 9.5% to 7.5%
A small 2008 pilot trial put berberine head-to-head with metformin in newly diagnosed type 2 diabetes, and the glucose-lowering effect looked similar. In the berberine group, HbA1c fell from 9.5% to 7.5% in three months. A second trial in 48 people already on treatment saw HbA1c drop from 8.1% to 7.3% and HOMA-IR fall 44.7%. But these were small studies in people with diabetes, and about a third of participants had GI side effects. Here is what the data show, what they don't, and what to know before you think about berberine.
The Gut Bacterium That Worked Better Dead: Akkermansia's 29% Edge
In the first human trial of Akkermansia muciniphila, the pasteurized (heat-killed) version, not the live one, produced the headline results. Insulin sensitivity rose 28.62% and fasting insulin fell 34.08% versus placebo in overweight, insulin-resistant adults. The weight and fat changes everyone hopes for did not reach statistical significance, and several authors hold patents and co-founded a company selling the bacterium. Here is what the study found, what it can't tell you, and what to check before buying a supplement.
NMN's First Human Win: 250 mg a Day Lifted Muscle Insulin Sensitivity by About 25% in Prediabetic Women
NMN has long been a darling of the longevity market, but human evidence was thin until a 2021 Washington University trial published in Science. In postmenopausal women with prediabetes who were overweight or obese, 250 mg of NMN daily for 10 weeks improved muscle insulin sensitivity by roughly 25%. Muscle insulin signaling and genes tied to muscle remodeling also improved, while the placebo group saw no change. But the benefit was narrow, and the study did not show NMN lowering blood sugar or reversing prediabetes. Here's what the trial found, who it applies to, and what it didn't change.