Recommended labs for peptide users (community-maintained)
33 posts
Pinning this so we stop answering 'which labs should I pull' in 40 different threads. This is a living list — reply with additions/corrections and I'll fold them in.
Tier 1 — pull before ANY cycle, repeat ~8-12 weeks in:
- CBC w/ diff
- CMP (glucose, BUN, creatinine, eGFR, AST, ALT, ALP, bilirubin, albumin, electrolytes)
- Lipid panel (TC, LDL, HDL, Trigs) — add ApoB if you can afford it
- HbA1c + fasting insulin (for HOMA-IR)
- TSH
- Total testosterone (men)
- IGF-1 if you're touching anything GH-adjacent
Tier 2 — cycle-dependent, add based on what you're running:
- GH stacks: IGF-1, IGFBP-3, fasting glucose+insulin, HbA1c, prolactin (hexarelin/ghrelin-mimetic users)
- GLP-1s: ApoB, lipid panel, HbA1c, lipase (baseline), amylase optional
- BPC/TB-500: LFTs (AST/ALT/ALP), hs-CRP if you're tracking inflammation
- Long courses of anything: Cystatin C > serum creatinine for kidney tracking
Tier 3 — nice-to-have, cheap add-ons:
- Vit D 25-OH
- Ferritin + iron panel
- Homocysteine (especially if on GLP-1 / B12 absorption story)
- hs-CRP
- Magnesium RBC (not serum — serum is useless)
Draw conditions that matter:
- Fasted 10-12h for lipids, glucose, insulin
- IGF-1: time of day matters less than people claim, but be CONSISTENT draw-to-draw
- Cortisol: 7-9am draw, fasted
- Prolactin: not after nipple stimulation (yes really), not immediately post-workout
Lab choice: LabCorp and Quest are broadly interchangeable but DON'T mix them within a cycle — reference ranges and even assay methods differ. Pick one and stick.
Reply with additions. I'll edit this post as consensus forms.
- MOTS-c · 10 mg · weekly · sub-Q
- 5-Amino-1MQ · 100 mg · daily AM · oral
22 Replies
31 posts
+1 to ApoB-as-standard. Non-HDL-C is a decent proxy if you literally cannot get ApoB but ApoB is the real answer.
27 posts
Endorsed. One nit: for Tier 1 I'd move ApoB up from 'if you can afford it' to standard. LabCorp charges ~$17 cash through Ulta/Marek if you're not going through insurance. No excuse.
- Sermorelin · 300 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
44 posts
On IGF-1 timing — the half-life is ~15 hours so acute time-of-day swings are small, but there IS a real seasonal component (higher in summer in most populations). Not huge, but if you compare a winter baseline to a summer retest you'll see ~10-15 ng/mL variance independent of anything you're doing.
33 posts
Folded in. Updated Tier 3 to say 'Homocysteine + MMA for B-vitamin status'.
- MOTS-c · 10 mg · weekly · sub-Q
- 5-Amino-1MQ · 100 mg · daily AM · oral
12 posts
Please add methylmalonic acid (MMA) as an option alongside homocysteine for B12 status. Homocysteine alone misses ~15% of B12 deficiencies because folate masks it. MMA is more specific.
50 posts
Cystatin C mention deserves to be louder. Creatinine is a muscle-mass confound — if you're gaining LBM on a GH stack your serum creatinine goes up for REASONS THAT HAVE NOTHING TO DO WITH YOUR KIDNEYS. I've watched people panic over a 1.15 mg/dL reading that just reflected 6 lbs of LBM.
33 posts
For HbA1c, remember it integrates ~90 days of glucose so a 6-week retest doesn't capture the full change. Fructosamine is better for short windows (~2-3 weeks).
10 posts
hs-CRP note: a single reading is almost useless. It swings wildly with minor illness, tooth pain, overtraining. Need 2-3 readings spaced a week apart to get a real baseline.
46 posts
Stickied. Keep the additions coming, we'll refresh every few months.
- Sermorelin · 200 mcg · 5x/wk AM · sub-Q
- BPC-157 · 250 mcg · 2x/day · sub-Q
39 posts
Can we add a note on 'reference range' vs 'optimal range'? Most reference ranges are 95% CI of a reference population that includes a lot of metabolically unhealthy people. Being 'in range' at LDL-C 159 isn't the goal.
71 posts
Second this. Reference range for fasting insulin at LabCorp is 2.6-24.9 mIU/L — a 22 reading is 'normal' and also quietly terrible.
- BPC-157 · 500 mcg · 2x/day · sub-Q
- GHK-Cu · 2 mg · nightly topical · topical
45 posts
Not strictly a blood lab but DEXA every 6 months belongs on this list for anyone on GH/tesa/GLP-1s. Scale weight lies, body comp shifts don't.
32 posts
For GLP-1 users — baseline lipase is worth doing once so you have a pre-cycle number if anything goes sideways. Most people never get a baseline and then panic if they pull one mid-cycle.
115 posts
Gently — can we tag which recommendations are evidence-backed vs 'community consensus'? Some of these are solid (ApoB, HbA1c) and some are more vibes-based.
33 posts
Fair. I'll add a [E] tag for evidence-backed and [C] for community-consensus in the next edit pass.
- MOTS-c · 10 mg · weekly · sub-Q
- 5-Amino-1MQ · 100 mg · daily AM · oral
71 posts
Appreciated. The 'Cystatin C > creatinine' claim in particular has good evidence behind it, whereas 'fasted AM IGF-1' is more convention than necessity.
34 posts
Also — 'tier 1' labs run ~$80-120 cash through a discount service. Worth stating explicitly so people don't think this requires insurance.
33 posts
Added SHBG to Tier 1 for men. Thanks.
- MOTS-c · 10 mg · weekly · sub-Q
- 5-Amino-1MQ · 100 mg · daily AM · oral
94 posts
Can we add SHBG to tier 1 for men? It's cheap, and it moves meaningfully on GLP-1s, tesa, and anything that changes insulin sensitivity. Without it, total T is harder to interpret.
- CJC-1295 no DAC · 100 mcg · pre-bed · sub-Q
- Ipamorelin · 200 mcg · pre-bed · sub-Q
- BPC-157 · 250 mcg · 2x/day · sub-Q
9 posts
22 posts