HCG (Fertility) (HCG for Ovulation Trigger (Pregnyl/Ovidrel))
Used as an ovulation trigger in assisted reproduction protocols. The LH-mimicking activity of HCG causes final oocyte maturation and ovulation approximately 36 hours after injection, timing intercourse or egg retrieval.
How it works
Binds LH/CG receptors on the dominant follicle, triggering resumption of meiosis in the oocyte, luteinization of granulosa cells, and follicular rupture (ovulation) within 36-40 hours of administration.
Key facts
- Molecular weight: ~36,700 Da
- Half-life: ~33 hours
- Bioavailability: ~100% (subcutaneous/intramuscular)
- Storage: Refrigerate. Reconstituted: use within 30 days.
Dosing overview
- Typical dose: 5000-10,000 IU (Pregnyl) or 250 mcg (Ovidrel)
- Frequency: Single injection timed to follicle maturity
- Duration: Per cycle
- Route: Subcutaneous or intramuscular
Reported benefits
- Precise ovulation timing
- Final oocyte maturation
- Corpus luteum support
- IUI/IVF timing coordination
- Luteal phase support
Possible side effects
- Ovarian hyperstimulation risk
- Bloating
- Breast tenderness
- Mood changes
- Pelvic discomfort
- Multiple pregnancy risk
Research
- HCG trigger timing in IUI cycles (2021): HCG trigger at 18mm follicle size optimized pregnancy rates (22% per cycle) vs earlier or later trigger timing.
- Dual trigger (GnRH agonist + low-dose HCG) (2022): Dual trigger reduced OHSS incidence by 90% while maintaining equivalent oocyte yield in high-responder IVF patients.
Community reviews of HCG (Fertility)
- quiet_gains rated it 5/5 - Worth adding to the protocol: HCG (Fertility) has been a worthwhile addition. I am data-driven and tracked relevant markers before, during, and after. The improvement is measurable and correlates with the intervention timeline. What sets this apart from some compounds I have tried is the consistency. Benefits did not fluctuate wildly or disappear. They built up and maintained. That gives me confidence in the mechanism. Tolerance has been excellent. Nothing in my bloodwork or subjective experience raised any flags. This is the kind of compound that does its job quietly without causing problems. Exactly what you want.
- stack_logic_lisa rated it 5/5 - Genuinely effective after 2 months: Been using HCG (Fertility) for about 2 months and the results are clear. Not overnight dramatic, but a steady, consistent improvement that became undeniable by the end of the first month. The mechanism makes sense based on what I have read in the literature, and my subjective experience matches the expected timeline. Benefits built gradually and plateaued at a good level. Side effects were minimal to none at the dose I used. Followed proper protocols for sourcing, storage, and administration. Would recommend to others who have done their research and have realistic expectations.
- loading_phase_lucy rated it 5/5 - Noticed clear benefits within weeks: Added HCG (Fertility) to my protocol about 2 months ago and it has earned its place. The benefits became noticeable around week 2-3 and have been consistent since. What I appreciate about this compound is the predictability. It does what the research suggests it should do, at roughly the timeline you would expect. No surprises, no dramatic swings, just steady improvement. No notable side effects to report at my dose. Sourcing is always the challenge with research compounds, insist on third-party testing. Storage and reconstitution per standard protocols. Plan to continue.
- greg_labrat rated it 4/5 - Timing got much cleaner for me: For me the main thing was the timing, my clinic cycles felt a lot less messy after about 12 weeks on HCG trigger support. I am in the Netherlands, work long software hours, so not having to second-guess the ovulation window was the big win. Small caveat, injections are a faff.
- calmerin rated it 4/5 - Good timing, but the bloat was a bit annoying: I used HCG for about 4 weeks around fertility timing, because in Sweden I like things very measured and my schedule is already a bit too tidy. It did what I wanted for ovulation coordination, but I felt noticeably bloated and a bit off in my mood for a few days after.
- theo_benchpr rated it 5/5 - Tight timing, fewer surprises, finally: I’m in my late 30s, work long hours as a software engineer, and I train pretty hard, so I wanted something that made the timing side of fertility less chaotic. For me, HCG over about 4 months seemed to do exactly that. Things felt more predictable, and that took a lot of stress off my week (which matters when you’re juggling deadlines and a lifting schedule in East Coast traffic). I’m not saying it’s some universal fix. This was just my own experience, but it clearly helped enough that I’d use it again if I needed that kind of timing support.
Compare HCG (Fertility)
Research and educational reference only. Not medical advice.