NNT and NNH for GLP-1: Number Needed to Treat

Pharmaceutical marketing loves averages: "15% average weight loss!" But averages hide a critical question: how likely is it to work for you? The Number Needed to Treat (NNT) answers this more honestly -- and for GLP-1 medications, the NNT numbers are remarkably favorable.

What Is NNT?

NNT is the number of patients who must be treated with a medication for one additional patient to achieve a specific outcome compared to placebo. An NNT of 1 would be a perfect drug (works for everyone). An NNT of 100 means only 1 in 100 patients benefits beyond placebo. For context, statin drugs for heart attack prevention have NNTs of 50-100. Blood pressure medications have NNTs of 15-25. GLP-1 medications for weight loss? NNTs of 2-4 for clinically meaningful outcomes.

GLP-1 NNT Values

These are extraordinary NNTs. An NNT of 2 for 10%+ weight loss on semaglutide means that for every 2 patients treated, 1 achieves clinically meaningful weight loss who would not have otherwise. No other class of weight loss medication comes close to these numbers.

Number Needed to Harm (NNH)

NNH measures how many patients need to be treated before one experiences a specific harm beyond what would occur with placebo. Higher NNH means a safer drug.

The Benefit-Risk Ratio

Comparing NNT to NNH gives a clear picture of benefit vs risk. For semaglutide: NNT of 2 for meaningful weight loss vs NNH of 14 for discontinuation -- meaning the benefit-to-risk ratio is approximately 7:1. For every patient who stops due to side effects, 7 patients achieve clinically meaningful weight loss. This is among the most favorable benefit-risk ratios in all of medicine.