Dried root of a southern African plant, taken orally as a bitter extract for aching joints and a sore back. Short courses ease flares of long-standing low back pain; hip and knee osteoarthritis results are mixed. Indigestion and diarrhoea are predictable, and no long-term safety data exist. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Haemoglobin | Men 14.0–15.5 g/dL; women 13.0–14.5 g/dL | Detects occult gastrointestinal blood loss |
| Ferritin | 50–100 ng/mL | Falls before haemoglobin in slow gastrointestinal bleeding |
| Serum sodium | 138–142 mmol/L | Targets the reported inappropriate antidiuretic hormone secretion |
| Blood pressure | <120/75 mmHg | Targets the reported raised-pressure case |
| Alanine aminotransferase | Men <25 U/L; women <20 U/L | Confirms the liver is unaffected over a course |
| Estimated glomerular filtration rate | >90 mL/min/1.73 m² | Kidney clearance, and eligibility given rare reports of herb-related kidney injury |
| Fasting glucose | 75–90 mg/dL | Baseline before any additive glucose lowering |
| High-sensitivity C-reactive protein | <1.0 mg/L | Tracks the inflammatory process the root is meant to act on |
| Serum uric acid | 3.5–5.5 mg/dL | Optional, given the rodent urate-lowering finding |
| WOMAC or visual analogue pain score | No established target; 20% improvement from own baseline | Converts a symptom into a comparable number |
Cadence: Blood pressure twice weekly for the first four weeks, then monthly; sodium and a full blood count at 4 weeks and 12 weeks; liver enzymes, kidney function, fasting glucose and inflammatory markers at 12 weeks, and thereafter only if a course is repeated.