Comparison
Alpha-GPC vs Clomiphene
Side-by-side of Alpha-GPC and Clomiphene. Every row below is pulled from the compound schema and will update as our data grows. For deeper reads, follow through to each compound page.
Alpha-GPC
Alpha GPC supplement profile: 300 to 600 mg dosage, acetylcholine synthesis, attention and reaction-time evidence, side effects, and choline donor comparisons.
Clomiphene
Clomiphene citrate raises LH/FSH and endogenous testosterone in men. SERM TRT alternative, 25 to 50 mg, fertility preserved, visual side effects flagged.
Effects at a glance
Alpha-GPC
- •Choline donor supplement, roughly 40% choline by weight; crosses blood-brain barrier efficiently
- •Replicated small gains in attention and reaction time at 300 to 600 mg in healthy adults
- •Standard prescription cognitive medication in much of Europe (Gliatilin) at 1,200 mg/day for vascular cognitive impairment
- •ASCOMALVA trial (n=210) showed cognitive preservation when added to donepezil over 24 months
- •Increases acute power output (~14%, single trial) and transient growth hormone secretion at 600 mg
- •TMAO production raises a contested cardiovascular concern at chronic high doses
Clomiphene
- •SERM that blocks estrogen-receptor negative feedback at the hypothalamus, raising LH and FSH
- •FDA approved 1967 for ovulation induction in anovulatory women at 50 to 100 mg cycle days 5 to 9
- •Off-label in men at 12.5 to 25 mg daily raises endogenous testosterone while preserving fertility
- •Enclomiphene (trans-isomer) is preferred for male use; cleaner PK and less estrogenic side effect burden
- •Visual disturbances occur in ~1 to 2% of users; persistent symptoms warrant immediate cessation
- •Letrozole has displaced clomiphene as first-line ovulation induction in PCOS (Legro 2014)
Side-by-side
| Attribute | Alpha-GPC | Clomiphene |
|---|---|---|
| Category | supplement | pharmaceutical |
| Also known as | L-Alpha glycerylphosphorylcholine, choline alfoscerate, GPC, alpha-glyceryl phosphorylcholine | Clomid, clomiphene citrate, Serophene, enclomiphene |
| Half-life (hr) ↗ | 4 | 168 |
| Typical dose (mg) ↗ | 600 | 25 |
| Dosing frequency | 1 to 3 times daily | 5-day pulse cycle days 5 to 9 (women); daily or every other day (men, off-label) |
| Routes | oral | oral |
| Onset (hr) | 1 | 6 |
| Peak (hr) | 2 | 7 |
| Molecular weight | 257.22 | 405.96 |
| Molecular formula | C8H20NO6P | C26H28ClNO |
| Mechanism | Hydrolyzed to free choline and glycerophosphate after absorption; choline supports acetylcholine and phosphatidylcholine synthesis in CNS. | Selective estrogen receptor modulator that antagonizes estrogen at the hypothalamus and pituitary, increasing GnRH and gonadotropin output, which drives gonadal steroidogenesis. |
| Legal status | Dietary supplement (US); prescription medication in much of Europe | Prescription only (FDA approved for ovulation induction; off-label in men) |
| WADA status | allowed | banned |
| DEA / Rx | OTC supplement | Rx only (not a controlled substance) |
| Pregnancy | Insufficient data; choline generally recommended in pregnancy | Category X; contraindicated in pregnancy |
| CAS | 28319-77-9 | 911-45-5 |
| PubChem CID | 71920 | 1548953 |
| Wikidata | Q411478 | Q416785 |
Safety profile
Alpha-GPC
Common side effects
- mild GI upset
- headache
- dizziness
- occasional insomnia with evening dosing
Contraindications
- established cardiovascular disease (TMAO concern)
- concurrent strong anticholinergic therapy
Interactions
- anticholinergic medications: partial mutual antagonism(minor)
- cholinesterase inhibitors (donepezil): additive cholinergic effect, basis for ASCOMALVA protocol(minor)
- scopolamine: partial counteraction of anticholinergic effect(minor)
Clomiphene
Common side effects
- hot flushes
- mood changes
- abdominal discomfort
- breast tenderness
- visual disturbances (rare)
- headache
Contraindications
- pregnancy
- active liver disease
- ovarian cysts (not PCOS-related)
- uncontrolled thyroid or adrenal disorder
- abnormal uterine bleeding of undetermined origin
- hormone-sensitive cancer
Interactions
- tamoxifen: competing SERM activity; not used together(moderate)
- ospemifene: competing SERM activity(moderate)
- anastrozole: additive estrogen reduction; sometimes combined in male protocols(minor)
- TRT (exogenous testosterone): TRT suppresses HPT axis that clomiphene targets; do not combine(moderate)
Which Should You Take?
Alpha-GPC comes out ahead for most readers on the criteria we weight: 3 catalogued goals, OTC dietary supplement, oral dosing, with a Tier-B outcome catalogued. Clomiphene is the right call when one of the conditionals below applies.
- → If your priority is focus or working memory, pick Alpha-GPC.
- → If your priority is athletic performance, pick Alpha-GPC.
- → If your priority is hormonal optimization, pick Clomiphene.
- → If your priority is fertility, pick Clomiphene.
Edge case: If you want to avoid prescription-only, Alpha-GPC is the more accessible choice.
Default choice: Alpha-GPC. Lower friction to source, and broader goal coverage. Reach for Clomiphene only if your priority sits squarely in the goals it owns above.
This verdict is generated from each compound's schema (goals, legal status, evidence outcomes, dosing route). It updates automatically as our compound data evolves; the deeper read sits on each individual compound page.
Common questions
What is the difference between Alpha-GPC and Clomiphene?
Alpha-GPC and Clomiphene differ in category (supplement vs pharmaceutical), mechanism, and typical dosing. See the side-by-side table for full details.
Which has a longer half-life, Alpha-GPC or Clomiphene?
Alpha-GPC half-life is 4 hours; Clomiphene half-life is 168 hours.
Can you stack Alpha-GPC with Clomiphene?
Stack compatibility depends on mechanism overlap, legal status, and individual response. Check each compound page for specific interactions and contraindications before combining.
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