Peptide Education

One in eight US adults is on a GLP-1, and patients now ask for BPC-157 by name. This is the map: what is proven, what is under study, what the safety record shows and where the real risk sits.

The first insulin injection was given in January 1922. More than 80 peptide drugs later, the class is mature medicine, and chemistry solved most of its old limits.

Tirzepatide and semaglutide now make up most of the sales of the two companies that own them. Behind that are tens of millions of patients, demand no alert has slowed, and a parallel market in its shadow.

The regulators’ criticisms are real. So are more than 80 approved peptide drugs, growing demand and the results clinicians report. The supporters’ arguments, in their own words.

The phase 3 trials were published in September 2026. Long before that, retatrutide was sold online as ‘research use only.’ The molecule is strong. The channel is the problem.

In 2002, mice lacking the GIP receptor resisted obesity. Two decades later, an agonist of that receptor, paired with GLP-1, beat semaglutide head to head. What explains the paradox, and where the evidence ends.

Amylin leaves the beta cell with insulin and curbs food intake through a pathway distinct from GLP-1. From pramlintide in 2005 to once-weekly cagrilintide, this is what the trials show and where they stop.

The next obesity drugs arrive with double-digit numbers. The same molecule can ‘lose’ 20.4% or 22.7% depending on the estimand. Read the analysis before you compare.

Heart attack, kidney, sleep apnea, fatty liver, heart failure and the knee: six areas where semaglutide or tirzepatide already has randomized phase 3 trials. This is the evidence that makes the class more than a weight-loss treatment.

Patients ask four questions about semaglutide and tirzepatide: muscle, regain, vision and the pancreas. The trials and regulators have answers for each.

The boxed warning is still on the label. A French study found a signal. The large registries that followed did not. Medullary carcinoma is still too rare to rule out.

Cohorts link GLP-1 agonists to less dementia, and one Parkinson’s trial was positive. The large semaglutide Alzheimer’s trials and the phase 3 exenatide Parkinson’s trial were negative.