GABA is the body's calming signal, sold as an oral supplement. Whether an oral dose reaches the brain has never been settled. Small studies point toward faster sleep onset, steadier mood under pressure and a modest fall in blood pressure, but each rests on one study or is contradicted by another. Safety looks favourable at studied doses. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Seated blood pressure | 110–120 / 70–80 mmHg | The compound's most consistent physiological effect |
| Standing blood pressure | Systolic fall under 20 mmHg on standing | Postural drop causing light-headedness and falls |
| Resting heart rate | 50–65 beats per minute | The parasympathetic shift GABA is proposed to produce |
| Heart rate variability | No established target; change from own baseline over four weeks | Objective correlate of the calming nerve-balance shift |
| Fasting glucose | 75–90 mg/dL (4.2–5.0 mmol/L) | Screens the metabolic claim trials did not support |
| Glycated haemoglobin | 4.8–5.3% | Average blood sugar over roughly three months |
| Insulin-like growth factor 1 | Mid-point of the age-adjusted reference range | Sustained growth signalling from gram-level dosing |
| Prolactin | Under 15 ng/mL (men), 20 ng/mL (non-pregnant women) | Gram-level dosing altered this pituitary hormone |
Cadence: Blood pressure and standing tolerance at two weeks and three months; sleep measures at four weeks; blood markers every six to twelve months, or sooner at gram-level dosing.