A "loading phase" is a higher-than-maintenance dose for a short period at the start, used to build up tissue or receptor levels faster than maintenance dosing alone would. Not every peptide needs one. Skipping it on the ones that do is the most common reason "the peptide isn't working" in week 4.
Peptides that NEED a loading phase:
- TB-500 — load at 5 mg twice weekly for 4-6 weeks, then drop to 2.5-5 mg weekly maintenance. Without loading, tissue concentration takes 2-3x longer to reach effective levels.
- MT-2 — load at 0.25-0.5 mg/day for 7-14 days until target pigment is reached, then drop to 0.5-1 mg/week to maintain. Without loading, you'll never see meaningful pigment shift.
- MT-1 — same loading pattern as MT-2 but cleaner side-effect profile.
- GHK-Cu (sub-q) — some users load at 2 mg/day for the first week to "kick" connective tissue response, then drop to 1 mg/day. Less universally needed than TB-500.
Peptides that DON'T need loading:
- BPC-157 — no loading. Steady daily dose from day 1.
- GLP-1 peptides (tirzepatide, retatrutide, semaglutide) — opposite of loading. They REQUIRE titration: start low, ramp up over weeks. Loading would cause severe GI side effects without benefit.
- Ipamorelin / CJC-1295 / MK-677 / Sermorelin — no loading needed. Daily dose builds GH-axis response steadily.
- Tesamorelin — no loading.
If your peptide isn't on the "needs loading" list and you skipped loading, that's not why it's not working. Look elsewhere.
"Nothing's happening" — the week 3-4 panic
This is the most common quit point. Something to know: most peptide effects accrue gradually over 4-12 weeks. What you feel in week 1-3 is rarely the meaningful signal.
Realistic timelines by class:
- Healing peptides (BPC-157, TB-500, GHK-Cu): subtle change week 3-4, real change week 5-8. If you're 2 weeks in and nothing's different, that's expected.
- GLP-1s: appetite suppression is immediate (week 1). Weight movement starts week 2-3 and is gradual (1-2 lb/week typical). Body comp changes accrue over months.
- GH-axis (Ipamorelin/CJC/MK-677/Sermorelin): subtle sleep + recovery improvements week 2-3. Body composition shifts week 6-12+. Skin/hair changes 12+ weeks.
- MT-1/MT-2: pigment changes start week 2 of loading and are visible by week 3-4.
- Nootropics (Selank, Semax): variable. Some users feel effect within a week, some don't notice anything.
If you're past the realistic window AND nothing's happening: check the troubleshooting section below before increasing dose.
Troubleshooting "not working"
Run through this checklist before assuming the peptide is the problem:
1. Was the peptide stored correctly?
- Reconstituted vials degrade fast at room temperature. If yours sat on the counter for 4 hours twice this week, you're injecting partially-degraded product. See Storage.
2. Are you actually injecting where you think you are?
- Sub-q means under the skin (into fat tissue). If your needle is too long or angle is wrong, you might be injecting intramuscular, which changes pharmacokinetics.
3. Is the source legit?
- Review your COA. Bunk product is a real possibility. See Spotting scam vendors.
4. Are you on the right dose?
- The dose ranges in Pepdex are wide because community ranges are wide. If you're at the bottom of the range and not responding, the bottom isn't enough for your body.
5. Is there a confounder?
- Sleep below 6 hours/night blunts almost every peptide effect. So does poor nutrition, alcohol > 4 drinks/week, untreated thyroid issues. If your foundation is shaky, peptides are noise on top of noise.
6. Is this the right peptide for the goal?
- BPC-157 won't fix nerve pain. Tirzepatide won't build muscle. MT-2 won't grow hair. Sometimes the protocol is wrong for the goal. See Stacking principles.
If the checklist doesn't reveal a problem and you're past the realistic timeline, then it's time to consider escalation.
When to up the dose
Most beginners ramp up too early. Some never ramp at all. The right time:
You can consider increasing dose if ALL three are true:
1. You've completed the realistic timeline window (4-8 weeks depending on peptide).
2. You're below the published high-end of community range.
3. You've ruled out confounders (storage, source, sleep, etc.).
Don't increase dose just because:
- "I want faster results" — peptides don't work that way.
- "Other people are at higher doses" — they have different bodies and different goals.
- "Week 1 felt promising and now it feels less" — that's habituation, not dose-failure.
How to escalate (when warranted):
- Increase by ~25-30% of current dose. Not 100%.
- Hold the new dose for at least 2 weeks before re-evaluating.
- Watch for new side effects — they'll appear at the new dose, not the old one.
Specific peptide notes:
- GLP-1s: have a recommended titration schedule (every 4 weeks for tirzepatide). Don't ramp faster than the schedule.
- MK-677: dose-response is steep above 25 mg. Up only by 5 mg increments.
- BPC-157: dose ceiling is fuzzy (200-1000 mcg/day range). If 250-500 isn't working, more probably won't either — switch tactics.
- MT-2: don't increase loading dose above 1 mg/day. Severe nausea + hypertension risk.
When to drop the dose
The other direction is just as important.
Drop dose if:
- Side effects are persistent or escalating beyond expected
- You're getting the result you wanted at this dose (no need to push further)
- You've hit a plateau and want to see if a "deload" + restart re-sensitizes you
- You want to extend the cycle but reduce total exposure
How to drop:
- 25-50% reduction is the typical move.
- Hold the new dose for 2-3 weeks. Effects fade slowly; don't drop again immediately.
Plateaus
If your weight loss stalls on a GLP-1, your strength stalls on a GH-axis stack, or your skin stops improving on GHK-Cu — you've hit a plateau. Common reactions:
Wrong move: Up the dose immediately.
Right moves (in order of usefulness):
1. Look at the foundations. Sleep, training, nutrition, stress. Plateaus are usually foundational, not pharmacological.
2. Track for 2 more weeks. A "plateau" of 7-10 days is normal noise.
3. Take a 1-2 week deload at half-dose. Sometimes resetting receptor sensitivity restores response.
4. Switch components. Tirzepatide → retatrutide. Ipamorelin → MK-677. Different mechanism, same goal.
5. THEN consider a dose increase if 1-4 didn't work.
When to stop entirely
Sometimes the answer is "this peptide isn't right for you." Signs:
- You're past the realistic timeline AND have ruled out confounders AND have tried one dose escalation AND nothing meaningful is happening.
- Side effects are persistent or worsening despite dose adjustments.
- Goal has changed — you don't actually need this anymore.
- A pre-existing condition has changed and the peptide is no longer appropriate.
Stopping isn't failure. It's data — you now know this protocol doesn't work for your body, and that informs your next attempt better than another 4 weeks of nothing would.
When to keep going past the realistic window
Some peptides genuinely take longer for some people. If you're at week 8 of BPC-157 for a chronic shoulder and you're noticing 20% improvement, that's a working protocol — you continue. Effects accrue further with continued use. Don't stop just because the calendar says you "should" be done.
The signal is improvement, not duration. A protocol that's working but slow is still working.
How to journal this stuff
Track:
- Dose changes (date + new dose)
- Subjective response 1-10 daily
- Side effects (yes/no, severity)
- Sleep + training + nutrition (the confounders)
- Photos / measurements weekly
The pattern over 8-12 weeks tells you what to do next better than your gut feeling does in any single week. See Journal & tracking.
Practical takeaways
1. Loading: required for TB-500, MT-1/MT-2. Not for BPC-157, GLP-1s (those titrate UP), GH-axis.
2. "Nothing's happening" at week 2-3 is usually expected. Most peptide effects are 4-12 weeks.
3. Before increasing dose, run the troubleshooting checklist (storage, source, dose, confounders, fit).
4. Increase by ~25-30%, hold 2 weeks, re-evaluate. Don't double up.
5. Plateaus aren't dose problems first. Check foundations and consider a deload before escalating.
6. Stopping is data, not failure. Sometimes the answer is "wrong protocol for me."