Sub-Q vs IM for Ipamorelin — is anyone actually doing IM and why

No, there isn't one. Ipa Sub-Q gives you Cmax at ~15-30min, half-life ~2hr, peak pulse is clean. IM is an artifact of AAS-brain. I've said this for years.

@cyclecraft mixed. Some rotate sites more aggressively and the Sub-Q issue resolves. Others just settle into IM and don't look back because they don't care about the marginal PK argument.

Agree. For GHRPs generally, Sub-Q is the right route. IM is fine, it's not harmful, it's just unnecessary and the needle is bigger.

Item 4 is real though. Some people get consistent injection site reactions on Sub-Q abdomen (welts, itching). Switching to IM thigh or glute can legitimately reduce this because the depot is deeper and the reaction manifests less. Not a PK argument, a tolerance argument.

@protocolpilot that's a fair addition. I hadn't framed it as a tolerance switch. Have you seen people move back to Sub-Q after the reaction calms or do they just stay IM?

AAS-brain is a real cultural factor. I came from TRT/AAS and my first 3 months of peptides I IM'd everything. Nothing bad happened. But it was habit, not reasoning.

I'll defend IM for one niche case: obese users with a thick Sub-Q fat layer. The bleb forms inside adipose tissue with poor vascularization and slow absorption. IM bypasses that. It's a minority of the population here but it exists.

As someone who is, indeed, syringe shy — Sub-Q insulin pins are a lot less scary than a 1" IM pin. That alone keeps me on Sub-Q and off the fence.

For Ipa specifically, PK modeling has the IM bioavailability as effectively equivalent to Sub-Q within measurement noise. The argument is purely practical: shorter needle, faster injection, lower soreness, same Cmax.

@bac_water_noob no, you don't aspirate Sub-Q. Sub-Q injections are into tissue without big vessels; aspiration is an IM practice that's even been deprecated in most clinical guidelines. Just pinch, pin, push.

Dumb follow up — for Sub-Q Ipa, does it matter if you aspirate? I was told never to aspirate Sub-Q.

Would be curious if anyone has comparative PK data for Ipamorelin Sub-Q vs IM in humans — Raun 1998 has some hexarelin data but Ipa specific comparative data is thin.

@citation_required it's thin for Ipa specifically. Most of the PK work is on the GHRP class as a whole. But the class PK is remarkably consistent.

Putting on record — I pin Ipa in the deltoid IM. It's habit. The deltoid is the only IM site I can do solo without dropping pants. Sub-Q abdomen I do separately for BPC. Neither is wrong, both work.

@taper_time agree. Adding this to my mental reply template for the next 'should I IM' question.

I think the most honest summary: Ipa Sub-Q is default because of convenience and PK equivalence. IM is a fine exception for specific tolerance or anatomy reasons. Neither is 'stronger.'

Been IMing ipa in the vastus lateralis for 6 cycles. No reason other than habit from test days. Switching to Sub-Q for the next one based on this thread.

Changed my mind here too. Been IM'ing for 3 years, switching. The convenience alone is worth it.

Great thread for the FAQ. Short answer: Sub-Q is the default, IM is fine if you have a reason.

Appreciated, thanks.

Super helpful for a beginner. I was overthinking route.