Known conflicts and timing rules that change the protocol when two compounds
share a window. Severity column is operator-grade, not regulatory: hard
means “don’t do this combo at all,” timing means
“separate them by hours or days,” watch means
“allowed but track the overlap.”
Hard conflicts (don’t stack)
| A | B | Why |
|---|
| IGF-1 LR3 |
Exogenous insulin |
Both depress blood glucose; stacking has produced fatal hypoglycemia.
Pick one or the other for a given session. |
| Multiple desensitising GHRPs at once |
(Hexarelin + Ipamorelin + GHRP-2 etc.) |
Receptor saturation outstrips recovery; one GHRP plus one GHRH is
the ceiling. See Cycling
Strategies. |
| Angiogenic stack (BPC + TB-500 + IGF-1) |
Active malignancy / recent cancer history |
Mechanism stack feeds existing tumours. Hard contraindication, not
a timing question. See
Cancer Risk and
Growth Factors. |
| MT-II or
PT-141 |
Active MAOI use |
Theoretical pressor interaction; community standard treats as hard
avoid. |
Timing conflicts (separate by hours)
| A | B | Rule |
|---|
| GH-axis (GHRH+GHRP) |
Any food or insulin |
Insulin blunts GH release. Inject on empty stomach, hold food
20–30 min after. Standard for Mod GRF + Ipamorelin pre-bed and
Tesamorelin morning fasted. |
| GLP-1 family |
Oral medications with narrow-window absorption |
Slowed gastric emptying shifts oral bioavailability. Time-sensitive
oral meds (thyroid replacement, certain antibiotics, oral
contraceptives) need 1–2 h spacing. |
| IGF-1 LR3 |
Pre/post-injection carbs |
30–50 g fast carbs immediately after the shot. Non-negotiable.
See Lean Mass and
Hypertrophy. |
| MT-II |
UV exposure |
Required pairing for tan to develop, but space loading-dose injections
from sun by 4–6 h to mute the autonomic flush. |
Watch (allowed, track the overlap)
| A | B | What to watch |
|---|
| MT-II |
PDE5 inhibitors (sildenafil, tadalafil) |
Synergistic erection effect; priapism risk if both are dosed close
together at high doses. Lower the PDE5 dose first time. |
| PT-141 |
Alcohol / sedatives |
Not a direct interaction, but PT-141 nausea + alcohol = much worse
tolerability. Skip alcohol on dosing day. |
| Thymosin Alpha-1 |
Corticosteroids |
Steroids may blunt Tα1’s immune-modulating effect.
Time-separate by at least one full dosing interval, or skip the Tα1
cycle while on steroid pulse. |
| Thymosin Alpha-1 |
Chemotherapy |
Studied in oncology adjunct settings; protocols are clinic-driven,
not biohacker-DIY. If the user is on chemo, this isn’t an
independent stacking decision. |
| GLP-1 family |
AAS / testosterone |
No direct conflict. The conflict is goal-level: AAS appetite is the
anabolic asset; GLP-1 appetite suppression undermines it. Pick one
protocol or the other for a given block. |
| GH axis |
AAS / testosterone |
Common, well-tolerated stack. Watch hematocrit (AAS-driven) and
IGF-1 / HbA1c (GH-driven) on the same panel cadence. |
| BPC-157 + TB-500 |
Standard healing pair |
Standard pair, no direct conflict. The cumulative-angiogenic-exposure
rule still applies - bracket with cycle washouts. See
Cycling Strategies. |
AAS-context overlap rules
- IGF-1 LR3 stacked under AAS: 4-week blast at the front
of an AAS cycle; do not run continuously. Hematocrit + glucose
monitoring already there from the AAS protocol covers it; add IGF-1
bracketing.
- GH axis under AAS: standard combo. The AAS protocol
already monitors lipids and hematocrit; add IGF-1 + HbA1c to that
cadence.
- BPC-157 / TB-500 under AAS: for joint or tendon
discomfort during an AAS cycle, fine. Cycle the healing peptides
independently of the AAS cycle - they don’t share a
PCT-style washout requirement.
- GLP-1 under AAS: the goal mismatch above. Almost no one
runs both simultaneously for body-comp goals.
- Don’t share SC injection sites between AAS oil and SC
peptides. The IM-vs-SC tissue depths are different; site
rotation rules in the Injection
Rotation Grid apply to SC zones only.
Procedural conflicts (timing matters)
- Don’t reconstitute a peptide with the same syringe just
used for a different peptide. Cross-contamination risk; tiny
volumes carry over.
- Don’t mix two peptides in the same vial unless
purchased as a verified blend. Stability differs across compounds;
a generic blend can degrade one component while the other is fine.
- Don’t pull from a reconstituted vial that’s past
its 28–30-day window. See
Cold-Chain Quick Reference.
Cross-references
