The US health secretary says he is a big fan of peptides. Many are promising drugs, but the only way to know their utility is proper clinical trials The US health secretary says he is a big fan of peptides. Many are promising drugs, but the only way to know their utility is proper clinical trials R obert F Kennedy Jr, the US health secretary, is a chaotic person, but his Make America Healthy Again (Maha) agenda tends to follow a predictable logic. Large-scale, mandatory public health