How to Read a Scientific Study

Who was studied, and does that population resemble the one being discussed? How many, and for how long? Was there a control group, and were participants randomised and blinded?

What was the primary outcome, and was it stated before the study began? Who funded it, and who conducted the analysis? Has anyone independent replicated it?

Species first

The single most useful habit is checking the species in the methods section before reading the abstract's conclusions. A large share of confident peptide claims trace back to rodent studies.