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IGF-1 LR3 vs MK-677 (Ibutamoren)
IGF-1 LR3 and MK-677 (Ibutamoren) are both growth hormone peptides, which is why they get recommended interchangeably — but they are different compounds with different origins. A mixed vial also keeps differently: about 30 days for IGF-1 LR3 against 60 for MK-677 (Ibutamoren). The table below sets out the differences. We give no dosing guidance.
Side by side, in plain English — what each one is, where they overlap and where they genuinely differ.
IGF-1 LR3Growth Hormone
MK-677 (Ibutamoren)Growth HormoneAt a glance
| IGF-1 LR3 | MK-677 (Ibutamoren) | |
|---|---|---|
| Category | Growth Hormone | Growth Hormone |
| Typical route | SubQ | Oral |
| Shelf life once mixed | ~30 days | ~60 days |
The differences that actually matter
Both are classed as Growth Hormone peptides, so they get compared constantly and are often researched for overlapping reasons.
Route of administration differs — IGF-1 LR3 is typically subq, MK-677 (Ibutamoren) is typically oral. That alone changes how convenient each one is to keep up with.
Once reconstituted, MK-677 (Ibutamoren) keeps noticeably longer than IGF-1 LR3 (~60 days vs ~30 days), so vial waste is a real difference between the two.
What IGF-1 LR3 is
It primarily exerts its effects by binding to the IGF-1 receptor, a transmembrane tyrosine kinase receptor, which then initiates intracellular signaling cascades, notably the PI3K/Akt and MAPK pathways, critical for cell growth, proliferation, and differentiation. This decreased binding to IGFBPs allows a greater proportion of IGF-1 LR3 to remain unbound and biologically active for a longer duration, contributing to its prolonged systemic presence and sustained anabolic signaling. It is crucial to remember that IGF
What MK-677 (Ibutamoren) is
MK-677, also known as Ibutamoren, functions as a non-peptide ghrelin receptor agonist, specifically targeting the growth hormone secretagogue receptor type 1a (GHSR-1a). This mechanism leads to sustained elevations of both GH and insulin-like growth factor 1 (IGF-1) levels in the body, typically over a 24-hour period due to its approximate 24-hour half-life. It is sometimes explored in conjunction with other research compounds that target muscle protein synthesis or fat metabolism. This compound is intended for res
How to compare them for yourself
Anecdotes online are noisy because nobody is measuring the same thing. The only comparison that means anything is your own: log each entry with a timestamp, keep the vial ledger honest so you know what you actually got through, pick two or three metrics before you start, and look at the trend after several weeks rather than day to day.
Peptide Wizard does that part for you — IGF-1 LR3 and MK-677 (Ibutamoren) are both in the built-in reference library with a 3D vial, and your history, vial ledger and cost per entry stay private on your device.
FAQ
What is the difference between IGF-1 LR3 and MK-677 (Ibutamoren)?
Both are classed as Growth Hormone peptides, so they get compared constantly and are often researched for overlapping reasons.
Can you log IGF-1 LR3 and MK-677 (Ibutamoren) in the same period?
Plenty of people record more than one peptide at a time. Peptide Wizard keeps a separate vial ledger and entry history for each, so you can see exactly what overlapped and when — it does not recommend combinations or doses.
Which is better, IGF-1 LR3 or MK-677 (Ibutamoren)?
There isn't a universal answer — reported responses vary a lot between individuals, which is why your own log is more informative than anyone else's anecdote. Track one variable at a time and compare your own metrics over several weeks.
Is this medical advice?
No. This page is educational reference material only. It contains no dosing guidance. Speak to a qualified healthcare professional before making any decisions.
Handling questions
Whichever you pick, mixing and storage work the same way. Search the guides and land straight on the answer.
Can I shake it? · It went cloudy · Should I filter? · Fridge or freezer?
See all peptide comparisons →
Educational reference only. This page contains no dosing guidance and is not medical advice.