Common (>10% of users, dose-dependent):

• Acne and oily skin from peripheral 5α-reductase conversion in skin (skin has high 17β-HSD5 + 5α-reductase expression — DHEA pushes substrate into the DHT pathway locally).
• Scalp hair shedding / accelerated androgenetic alopecia in predisposed men (same DHT-mediated mechanism).
• Mild emotional reactivity, irritability, occasional aggression — pro-androgenic CNS signal.
• Mild sleep onset disturbance if dosed PM (pro-arousal GABA-A negative allosteric modulation).

Less common (1-10%):

• Gynecomastia or nipple sensitivity from peripheral aromatization to E2 (especially in higher-BMI users, where adipose aromatase load is high).
• Voice deepening, hirsutism, clitoromegaly in women (androgenic conversion).
• Menstrual irregularity in premenopausal women.
• HPG axis suppression — exogenous androgens/estrogens feed back on hypothalamus → reduced LH/FSH → reduced endogenous testicular T production. Suppression is mild at 25-50 mg but measurable at 100+ mg in young men with intact HPG.
• Mild insulin sensitization (modest benefit in older adults; clinically irrelevant in young healthy adults).
• Modest LDL/HDL lipid shifts (variable direction; usually trivial).

Rare-serious (<1% but worth knowing):

• Hormone-sensitive cancer risk (prostate, breast, ovarian, endometrial). No causal RCT but mechanistically plausible — sustained elevation of circulating T and E2 is a known driver of growth in hormone-sensitive tumors. Absolute contraindication with personal history of these cancers; strong relative contraindication with first-degree family history. The user's family history of these cancers is currently TBD in his profile and should be captured before any future reconsideration of DHEA.
• Hepatotoxicity at supraphysiological doses (>200 mg/day, rare; transaminitis reversible on discontinuation).
• Mood destabilization / mania induction in bipolar-spectrum users (case reports; mechanism via neurosteroid NMDA modulation + aromatized E2 effects on mood circuits).
• Polycythemia (elevated hematocrit) at higher doses — rare in DHEA monotherapy, more common when stacked with exogenous T.

Pregnancy / breastfeeding: Hard contraindication. Androgenic + estrogenic conversion contraindicated; placental transfer and fetal masculinization risk. Captured in hard-block YAML.

WADA / drug-tested athletes: Hard contraindication. DHEA is listed on the WADA Prohibited List S1.1b (anabolic androgenic steroids, endogenous). Banned in and out of competition. Detected via T/E ratio anomalies and DHEA-S/cortisol shifts on isotope-ratio mass spectrometry. Captured in hard-block YAML — disqualifying for amateur, collegiate, WADA-pro, USADA-pro, employer-tested, and military-tested tiers. Dylan is currently untested (and untagged in profile) but if he ever competes at a tested tier of MMA, this would auto-disqualify the molecule.

Specific watch periods: First 4-8 weeks for acne, skin, mood, libido shifts (the side-effect tells emerge by week 4). If used long-term, reassess full hormone panel + lipids + PSA (in men >40) every 3-4 months.