Alcohol
TL;DR — Hangover is an inflammatory event (CYP2E1 → ROS → NF-κB → IL-6/TNF-α), not acetaldehyde toxicity. Acetaldehyde doesn’t cross the BBB at social doses. Next-day biometric signature: HRV ↓ 30–50%, RHR ↑ 10–25 bpm, REM suppressed, recovery scores severely impaired 24–72 h. No commercial hangover supplement has ever been independently replicated in a human RCT. ALDH2*2 carriers (East Asian flush, 12–41% prevalence): acetaldehyde IS a direct toxin — drinking despite flushing dramatically increases oesophageal cancer risk (17.3× homozygotes, 14.5× heterozygotes vs 2.2× normal).
Key Facts
| Active compound | Ethanol |
| Primary receptor | GABA-A (α1/δ potentiation) |
| Secondary receptor | NMDA antagonism |
| Strongest biometric signal | HRV suppression + elevated RHR next morning |
| Hangover driver | IL-6/TNF-α inflammatory cascade, NOT acetaldehyde |
| Elimination rate | ~15–20 mg/dL/h; range 10–30+; zero-order at low, nonlinear at high |
| ALDH2*2 cancer risk | Oesophageal SCC: 17.3× (homozygotes), 14.5× (heterozygotes) vs 2.2× (normal ALDH2) — if drinking despite flushing |
| Main stack concerns | Retatrutide — flattened/delayed BAC curve (gastric emptying); reward modulation (GLP-1 VTA/NAc); triple agonist likely greater effect than semaglutide; glucagon agonism may compound alcohol-induced hypoglycaemia; interaction is continuous (7-day half-life) |
Pharmacokinetics
- Bioavailability: ~80% oral; first-pass metabolism modest at social doses
- Absorption: rapid from duodenum/jejunum; food delays but doesn’t reduce total
- Metabolism: ADH (low-EtOH) → ALDH → acetate → CO₂ + H₂O; CYP2E1 dominant at high BAC (~70–100% when BAC elevated)
- NAD⁺ depletion cascade: 2 NADH per ethanol molecule → elevated NADH/NAD⁺ ratio → (1) inhibits gluconeogenesis (blocks malate-aspartate shuttle) → hypoglycaemia; (2) inhibits β-oxidation → fatty acid accumulation → hepatic steatosis; (3) lactate accumulation (LDH reverse reaction)
- Sex differences: women have 70–80% lower gastric ADH → higher BAC per dose; smaller body water compartment; higher risk for alcoholic liver disease at equivalent consumption
Mechanism Map
- GABA-A potentiation → acute intoxication (inhibition)
- NMDA antagonism → glutamate rebound during withdrawal → hyperexcitability
- CYP2E1 → ROS → NF-κB → IL-6/TNF-α → hangover
- NADH/NAD+ elevation → inhibits gluconeogenesis → hypoglycaemia; inhibits β-oxidation → fatty liver
- Gut barrier disruption → endotoxin → Kupffer cells → TNF-α → systemic inflammation
- Acetate crosses BBB → adenosine-mediated CNS effects; brain uses acetate as fuel
Biometric Phases
Acute (0–4 h)
- HRV ↓ (RMSSD reduced), LF/HF ↑; sympathetic shift dose-dependent
- RHR may decrease slightly during early intoxication
Overnight
- Sleep onset latency ↓ (sedation); REM ↓ 20–50%; SWS ↑ first half, disrupted second half
- WASO ↑; overall sleep efficiency ↓
Next morning (6–24 h)
- RHR ↑ 10–25 bpm above baseline (dose-dependent)
- HRV (RMSSD) ↓ 30–50% of baseline
- Recovery/readiness scores severely suppressed; may not return to baseline for 24–72 h
Myths Debunked
- ❌ “Acetaldehyde causes hangover” — acetaldehyde does NOT cross BBB at social doses; cleared before hangover onset
- ❌ “Drink water prevents hangover” — necessary but grossly insufficient; primary mechanism is inflammatory
- ❌ “Hair of the dog works” — delays withdrawal, doesn’t resolve inflammatory cascade
- ❌ “GHK-Cu + alcohol = Fenton risk” — GHK copper is redox-silenced; antioxidant, not pro-oxidant
Detection
Alcohol detection model — HRV suppression + elevated RHR + sleep efficiency drop + motion context. Oura Gen4 most accurate (CCC=0.99, MAPE=5.96%).
Interactions
Alcohol peptide interactions — Retatrutide: flattened/delayed BAC curve, reward modulation (positive). BPC-157: gastroprotective (positive). TB-500: hepatoprotective, anti-inflammatory, anti-fibrotic (promising but preclinical). GHK-Cu: antioxidant (positive, concern unfounded).