Pick the peptide class you're starting. Read your week. Log symptoms in your journal. Compare. The exact day numbers vary — your timeline might run 1-2 days behind or ahead of the calendar. The pattern of progression matters more than the exact day.
GLP-1 peptides (tirzepatide, retatrutide, semaglutide) — first week
These are usually started at the lowest available dose for 4 weeks before titrating up.
Day 1 (injection day): Most users feel nothing for the first 6-12 hours. Some report mild appetite suppression starting that evening. No nausea typical on day 1.
Day 2: Appetite noticeably reduced. You'll find yourself "forgetting to eat" or eating much less per sitting. Some mild GI awareness — bloating, queasiness. No vomiting expected.
Day 3: Peak nausea day for many users. Often mild-to-moderate — not vomiting, just queasy. Eat small, low-fat meals. Dehydration starts to creep in if you're not drinking enough water.
Day 4: Nausea begins easing. Constipation may start (slowed gastric emptying). Start psyllium fiber + water if not already.
Day 5-6: Energy may dip — you've eaten substantially less for several days, electrolytes are depleted. Drink an electrolyte powder. Magnesium at night.
Day 7 (next injection day): Symptoms have usually plateaued. The next dose will reset the cycle but typically less intensely than week 1.
Red flags this week: persistent vomiting (more than 2x in a day), severe upper abdominal pain (especially radiating to back — possible pancreatitis), inability to keep liquids down for 24+ hours, signs of severe dehydration.
What you should NOT see: dramatic weight loss in week 1. Weight loss accrues over months. If the scale moves 5+ lb in a week, that's water/glycogen, not fat — normal but don't expect it to repeat.
MT-1 / MT-2 (loading phase) — first week
Loading dose is typically 0.25-0.5 mg/day for 7-14 days, sometimes lower for sensitive users.
Day 1: Inject before bed. 30-90 min later expect mild facial flushing and nausea. Sleep helps you skip the worst of it.
Day 2: Wake up feeling normal-ish. Mild residual facial flushing possible. Some users get a headache.
Day 3: Nausea on injection often peak day 2-3. After this it eases as tolerance builds. Pigment effects: nothing visible yet.
Day 4-5: First subtle pigment shift in some users — areas exposed to UV may darken slightly. Sun exposure during loading speeds the effect.
Day 6-7: Nausea profile usually milder than days 2-3. Pigment changes more visible. Energy and libido (MT-2 specifically) may shift up.
Red flags this week: any new mole or mole that changes shape/color (stop and see a derm), severe persistent nausea, allergic-type swelling.
GH-axis stack (Ipamorelin + CJC-1295) — first week
Day 1-3: Most users feel nothing different. Sleep may deepen the first few nights. No major immediate effect.
Day 4-5: Subtle: deeper sleep, vivid dreams, occasional pre-bed hunger spike if dosing late.
Day 6-7: First subtle "well rested" weeks. Body composition won't have shifted yet — that takes 4+ weeks. Mild facial puffiness possible (water retention from GH activation).
Red flags this week: hand tingling/numbness (carpal tunnel), persistent insomnia, glucose elevation if you have a CGM running.
MK-677 — first week
Day 1: Take in the morning if night dosing disrupts sleep, or vice versa. Mild hunger spike 1-2 hours after dose.
Day 2-3: Hunger noticeably increased. Sleep quality often improved (occasionally too vivid/wakeful for some users — switch dose to morning if that happens).
Day 4-5: Water retention noticeable on the scale (1-3 lb of water-weight gain is normal). Hunger driven by ghrelin pathway is high — eat real protein-rich meals to manage it.
Day 6-7: Pattern stable. If glucose is your concern, this is when to start CGM data collection — fasting glucose may run higher than normal.
Red flags this week: persistent fasting glucose above 110 mg/dL on CGM, severe hunger you can't manage, any vision changes (rare but reported on long-term high-dose use).
BPC-157 — first week
Day 1-3: Usually no perceptible effect. Some users report mild flushing at injection site. Existing pain or injury may feel marginally different but it's mostly placebo at this stage.
Day 4-7: Still mostly nothing systemic perceptible. Connective-tissue effects accrue over weeks, not days.
Red flags this week: spreading redness at injection site, fever, allergic-type swelling.
Important: BPC-157's effects build over 3-5 weeks. If you're not feeling anything in week 1, that's expected. Don't increase dose just because you're impatient.
TB-500 — first week
Day 1-3: Loading doses (5-7.5 mg). Some users report mild fatigue or "flu-like" feeling for 24-48 hours after first dose. Drink water, rest, it passes.
Day 4-7: Subtle tissue effects start, mostly imperceptible. Same as BPC-157 — real changes take weeks.
GHK-Cu — first week
Day 1-3: Inject sub-q, expect a brief metallic taste 30-90 seconds later. Mild facial flush possible. Skin: nothing visible yet.
Day 4-7: Subtle skin tone or texture change in early responders. Most users don't see anything visible until week 2-3.
Red flags this week: If you're using copper supplements at the same time, watch for symptoms of copper excess (nausea, fatigue, GI distress).
What to log in your journal this week
For any peptide, daily entries should capture:
- Time of dose
- Sleep quality (1-10)
- Energy through the day (1-10)
- GI symptoms (yes/no, severity)
- Injection-site reaction
- Mood
- Hunger level (relevant for GLP-1s and MK-677)
- Any unexpected symptoms
This gives you a baseline. By week 4, you can compare against this and see what's actually changed.
What this calendar is not
A medical decision tree. If symptoms diverge significantly from these patterns or if you're worried about anything, talk to a doctor. Pepdex content informs your understanding; it doesn't replace medical judgment for your specific situation.