Deer antler velvet

Tier 3 — weak evidence · IGF-1 · Athletic claims

Harvested from the soft cartilage of growing deer antlers and marketed for athletic performance and IGF-1 boosting. Multiple controlled trials found no significant improvement in strength, endurance, or testosterone levels in healthy adults. The IGF-1 content in supplements is too low to meaningfully affect blood levels. Not recommended for athletic use.

Dose: 500–1,500 mg/day; no meaningful performance benefit demonstrated in controlled trials