A West African shrub chewed as a tooth-cleaning stick and drunk by men as a strength tonic. One small human comparison found the stick about as good as a toothbrush. Hormone, sexual-function and blood-sugar claims rest only on animal studies, as do the liver and sperm harms. The human record is almost empty. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Alanine aminotransferase | Under 25 U/L men, under 20 U/L women | Most sensitive marker of liver-cell stress in animals |
| Aspartate aminotransferase | Under 25 U/L | Rose alongside alanine aminotransferase in rats |
| Alkaline phosphatase | 45–90 U/L | Shifted out of liver tissue into serum in rats |
| Total bilirubin | 0.2–0.8 mg/dL | Rose in the rat liver study; reflects clearance |
| Total testosterone | 600–900 ng/dL (adult men) | The primary outcome the intervention is taken for |
| Free testosterone | 15–25 ng/dL (adult men) | Reflects the fraction actually available to tissue |
| Luteinising hormone | 2–6 IU/L (adult men) | Distinguishes a pituitary-level effect from a testicular one |
| Fasting glucose | 75–86 mg/dL | Tracks the metabolic claim seen in rodent work |
| Glycated haemoglobin | Under 5.4% | Averages glucose over about three months |
| Prostate-specific antigen | Under 1.0 ng/mL (under 50), under 1.5 ng/mL (50–59) | Watches the theoretical androgen-sensitive risk |
| Sperm concentration and motility | Above 16 million/mL; motility above 42% | The one endpoint with a direct animal harm signal |
Cadence: Liver panel before starting, at 4 and 8 weeks, then after every subsequent course; hormones at 8 weeks; prostate-specific antigen every 6 to 12 months where use continues.