Last reviewed: January 2026
Add multiple peptides, set your vial and dose for each — get a complete weekly injection schedule.
→ Use this as a starting point, not a diagnosis. Online calculators provide estimates based on population averages. Your individual results may vary — consult a healthcare professional for personalized medical advice.
→ Measure consistently. For the most accurate tracking, take measurements at the same time of day under the same conditions each time you use this calculator.
→ Track trends, not single data points. One measurement is a snapshot. Track results over weeks and months to see meaningful patterns and progress.
→ Combine with related tools. Use this alongside other health calculators on this site for a more complete picture of your fitness and wellness metrics.
See also: GLP-1 Titration Tracker · Burnout Risk Calculator · TDEE Calculator · Max Heart Rate Calculator · Body Fat Calculator
A peptide stack calculator is a planning tool that helps you map out multi-peptide protocols — laying out which compounds you intend to use together, their individual dosing schedules, the timing of injections relative to meals or sleep, and the overall length of the cycle. The calculator does not prescribe protocols; it organizes information you supply so you can see your full schedule on a single screen and check it for obvious conflicts. Stacking is a research-context term that covers any protocol involving two or more peptides used in the same period, whether they target different tissues (skin and gut, for example), the same pathway via different mechanisms (a GHRH analog plus a GHRP), or sequential phases of a recovery process.1
Solo peptide protocols are simpler to evaluate, but combinations are common in published clinical research and in user-reported wellness practice because many bodily processes have multiple regulatory inputs. The pituitary growth hormone axis is the textbook example: one input pathway responds to growth hormone releasing hormone (GHRH) signals, another responds to ghrelin-mimetic signals (GHRPs). Activating both at once produces a larger, more physiologic GH pulse than either alone — which is why GHRH/GHRP combinations dominate growth hormone research literature. The same logic applies in tissue repair (BPC-157 for vascular and gastrointestinal tissue, TB-500 for muscle and ligament), skin and pigmentation, and metabolic protocols.
| Category | Common Pairings | Rationale | Typical Cycle Length |
|---|---|---|---|
| Growth hormone | CJC-1295 + Ipamorelin | GHRH analog + GHRP synergy | 8–12 weeks |
| Healing & recovery | BPC-157 + TB-500 | Different healing mechanisms | 4–6 weeks |
| Anti-aging research | Epithalon + GHK-Cu | Telomere/skin synergy | 10–20 days |
| Cognition research | Semax + Selank | Complementary neuro effects | 2–4 weeks |
| Metabolic research | Tirzepatide solo (rarely stacked) | Already dual-agonist | Per protocol |
*This table summarizes commonly discussed pairings in research literature and user reports. It is not medical advice and not a recommendation. Most peptides remain unapproved for self-administration outside an investigational setting.
Two peptides taken at the same wall-clock time are not necessarily acting at the same time inside your body. Half-life, route of administration, and food state all shift the effective overlap. A short-acting GHRP like Ipamorelin produces a GH pulse within 5–15 minutes and clears in about two hours, while a CJC-1295 with DAC has a half-life measured in days. Pairing the two means the long-acting partner is essentially always present, while the short-acting partner determines pulse timing. That's the entire mechanistic point — but it also means injecting them together once a day is a different protocol from injecting the GHRP three times a day with a constant CJC-1295 background. Your stack calculator should make this visible.2
Food state interacts with the GH axis specifically. A meal high in carbohydrate or fat blunts a GH pulse for roughly 60–90 minutes because circulating somatostatin rises after eating and somatostatin opposes GHRH/GHRP signals. Most growth hormone protocols therefore call for a fasted state of at least 60 minutes before and 30 minutes after a GHRP injection. Healing peptides (BPC-157, TB-500) and skin peptides (GHK-Cu) are not similarly food-sensitive, so they can be timed for convenience.
Stacking increases the surface area for adverse events in two ways: each individual peptide carries its own risk profile, and combinations can produce effects neither would alone. Examples worth knowing before any multi-peptide protocol:
GH-axis stacks and blood sugar. Growth hormone is naturally counter-regulatory to insulin. Strong, sustained GH elevation from aggressive GHRH/GHRP stacking can raise fasting glucose and reduce insulin sensitivity, particularly in people who are already at metabolic risk. Anyone with prediabetes, type 2 diabetes, family history of diabetes, or BMI >30 should treat this as a serious caveat and consider monitoring fasting glucose and HbA1c.3
Healing peptide stacks and active malignancy. The same growth and angiogenic signals that help repair injured tissue can theoretically support malignant tissue. The clinical literature on this is sparse and not definitive, but the standard precaution is to avoid systemic angiogenic peptides (BPC-157, TB-500) during active cancer treatment or with a recent cancer history.
Stacks involving GLP-1/GIP agonists. Tirzepatide, semaglutide, and retatrutide already work through multiple incretin pathways. Adding additional metabolic peptides on top is rarely justified by evidence and substantially increases the risk of nausea, gastroparesis, and gallbladder events. Most clinicians and researchers treat these as solo agents.
Subcutaneous injection volume. A practical limit for SQ injection is roughly 1 mL per site without local irritation. Stacking three peptides at once means you may need to spread injections across sites or schedule them at different times to keep volumes comfortable.
Many people new to stacks underestimate total weekly dose because the per-injection number looks small. A worked example: a research protocol of CJC-1295 (no DAC) at 100 mcg three times daily, plus Ipamorelin at 200 mcg three times daily, plus BPC-157 at 250 mcg twice daily, sums to 300 mcg + 600 mcg + 500 mcg per day, or 8,400 mcg = 8.4 mg per week of total peptide. The cost implications scale linearly: a 5 mg vial of each peptide may last only 1–2 weeks at this protocol level. Calculators that show weekly totals make the financial and logistical reality of a stack visible before you start.
| Stack Component | Per-dose | Frequency | Daily total | Weekly total |
|---|---|---|---|---|
| CJC-1295 (no DAC) | 100 mcg | 3×/day | 300 mcg | 2,100 mcg |
| Ipamorelin | 200 mcg | 3×/day | 600 mcg | 4,200 mcg |
| BPC-157 | 250 mcg | 2×/day | 500 mcg | 3,500 mcg |
| Stack total | — | — | 1,400 mcg | 9,800 mcg |
Cycling is the practice of using a peptide stack for a defined period followed by a deliberate off-period. The reasoning differs by category. For GH-axis peptides, receptor desensitization is the primary concern — continuous high-dose GHRP exposure produces tachyphylaxis (diminishing GH response over weeks), and an 8–12 week on / 4 week off pattern is typical in research protocols. For healing stacks, cycling is driven by the injury timeline — once the underlying tissue has resolved, there is no further pharmacologic target. Anti-aging cycles with epithalon are typically short (10–20 consecutive days) and repeated only 1–2 times per year.
A cycle planner should make these timelines explicit. Mixing a 12-week GH cycle with a 4-week healing cycle that ends mid-way through means you have two transitions to manage, not one. Plan the post-cycle interval, the gradual taper if the protocol calls for one, and the metrics you'll use to judge whether the cycle achieved its goal — body composition measurements, sleep quality scores, recovery rate after exercise, or specific symptom resolution.
Stacking magnifies the consequences of any single product being inaccurately labeled or contaminated. Two peptides combined in a single stack means double the chance of receiving a vial that is under-dosed, contaminated with bacterial endotoxin, or mis-identified. Reputable research-chemical suppliers publish HPLC purity certificates and mass spectrometry verification per batch. An anonymous supplier without published testing should not be trusted with your protocol regardless of price. Buying multiple peptides from a single tested source is generally safer than mixing suppliers in one stack.4
A spreadsheet or notebook is sufficient for stack tracking but the minimum data you should record is: date, time, peptide name, dose, injection site, what you ate beforehand, sleep score the night after, and any noticeable subjective effect. Two weeks of this kind of log usually reveals patterns — for example, that GH-axis pulses produce reliably better sleep on fasted-evening dosing but not on post-dinner dosing, or that BPC-157 timing relative to a chronic injury produces measurable difference within 14 days or doesn't. Without a log, you will misremember and adjust based on noise.
Tracking also matters when something goes wrong. A side effect that emerges in week three of a three-peptide stack is much easier to attribute if you have a log showing exactly when each component was added and at what dose. Without that record, you face the choice of dropping everything (losing whatever benefit the stack was producing) or adjusting blindly. Even a basic spreadsheet with columns for date, peptides taken, doses, and a 1–10 wellness score is enough to triangulate which component is responsible for which effect over a 30-day window.