Study Types
Double-Blind Study
A trial where neither participants nor researchers know who receives the treatment.
In a double-blind study, both participants and investigators are unaware of group assignments (treatment vs. placebo). This eliminates both participant expectation bias (placebo effect) and observer bias (researchers unconsciously favoring outcomes in the treatment group). Double-blinding is especially important in supplement research where subjective outcomes like energy levels, sleep quality, or hair appearance are measured. The blinding is typically maintained by using identical-looking placebo capsules and is revealed only after data collection is complete.