Protocol·Weight Management·Intermediate·Reviewed June 9, 2026
GLP-1 Companion Protocol.
A supportive stack for people losing weight on GLP-1 medications (such as semaglutide or tirzepatide), aimed at preserving lean mass and covering common nutrient gaps that can accompany reduced appetite and rapid weight loss. Adequate protein and resistance training are the foundation, these supplements are adjuncts, and all use should be coordinated with the prescribing clinician.
The glp-1 companion protocol in brief.
A quick summary. The full stack, with dose and timing for each supplement, is below.
The GLP-1 Companion Protocol is an intermediate stack of 7 supplements aimed at weight management: Creatine, HMB, Vitamin D3, Methylcobalamin, Calcium, Magnesium Glycinate, and Collagen Peptides. 3 are core and the rest are optional add-ons, at roughly $45-75/mo. Each supplement below lists its dose, timing, role, and the evidence behind it.
What is in the glp-1 companion protocol.
Dose, timing, role, and evidence tier for each supplement. Core items carry the protocol; optional ones are situational. Open any name for the full profile.
| Supplement | Dose | Timing | Role | Evidence |
|---|---|---|---|---|
| Creatine | 3-5 g monohydrate daily | Any time of day, taken consistently; daily intake matters more than exact timing | Core | Strong |
| HMB | 3 g daily, typically split into divided doses | With meals, around resistance training sessions | Optional | Emerging |
| Vitamin D3 | 1,000-2,000 IU daily (adjust to lab-confirmed status) | With a fat-containing meal for absorption | Core | Strong |
| Methylcobalamin | 500-1,000 mcg daily | Morning, with or without food | Optional | Moderate |
| Calcium | 500 mg elemental daily, used to top up dietary intake toward roughly 1,000-1,200 mg total | With a meal; if also taking iron or thyroid medication, separate by at least 2 hours | Core | Moderate |
| Magnesium Glycinate | 200-350 mg elemental daily | Evening, with food | Optional | Moderate |
| Collagen Peptides | 10-15 g daily | Any time; some people use it around training, others with a meal | Optional | Emerging |
Creatine supports muscle phosphocreatine stores and may help maintain strength and lean mass during a caloric deficit, complementing resistance training rather than replacing it. Pair it with adequate fluids and resistance exercise for best effect.
HMB (a metabolite of leucine) has been studied for reducing muscle protein breakdown, with the most relevant evidence during periods of muscle stress such as a caloric deficit or detraining. Results are mixed, so it is best viewed as an adjunct to sufficient dietary protein, and benefit is unlikely if total protein intake is already adequate.
Vitamin D3 supports bone health and normal muscle function, and deficiency is common, so reduced food intake during GLP-1 therapy can widen existing gaps. Dosing is best guided by a 25-hydroxyvitamin D blood level rather than assumed need.
Methylcobalamin is an active form of vitamin B12 that supports normal energy metabolism and nerve function, and lower food intake may reduce B12 sufficiency over time in some people. This is a gap-coverage measure, not a weight-loss agent, and persistent fatigue warrants clinical evaluation rather than self-treatment.
Calcium supports bone density, which is relevant because rapid weight loss can accelerate bone loss and reduced food intake may lower dietary calcium. Total intake (food plus supplement) should stay within standard guidance, so use the supplement only to fill the gap rather than to add a large fixed dose.
Magnesium Glycinate is a well-tolerated form that supports normal muscle and nerve function and may be gentler on the gut, which can help when appetite and food variety are reduced. Keep total supplemental magnesium within standard upper-limit guidance unless supervised by a clinician.
Collagen Peptides add an easy-to-consume protein source that may support connective tissue and joint comfort, which can be appealing when appetite is low and total protein is hard to reach. It is a lower-leucine protein, so it complements rather than replaces higher-quality protein for muscle maintenance.
How the pieces combine.
The mechanistic rationale for stacking these together rather than taking them in isolation.
- For people on GLP-1 medications (such as semaglutide or tirzepatide), rapid weight loss and reduced appetite raise the risk of muscle loss and nutrient shortfalls. Adequate protein and resistance training are the foundation here, these supplements are adjuncts, and all use should be coordinated with the prescribing clinician.
- Resistance training plus adequate dietary protein is the base; Creatine and HMB are studied as adjuncts to that combination, not substitutes, so prioritize training and protein first.
- Vitamin D3 and Calcium work together for bone health during weight loss; take both with a fat-containing meal, and let lab-confirmed vitamin D status guide dosing rather than stacking high fixed doses.
- Separate Calcium from any iron or thyroid medication by at least 2 hours, since calcium can reduce their absorption; coordinate timing with your prescribing clinician.
- Magnesium Glycinate in the evening pairs well with the daytime Methylcobalamin and Vitamin D3 routine, spreading minerals across the day while keeping total supplemental magnesium within standard upper-limit guidance.
- Collagen Peptides can top up total daily protein when appetite is low, but count it toward, not against, your higher-quality protein target since it is lower in leucine.
Cost and commitment.
A rough monthly cost and how involved the protocol is to run.
The evidence behind it.
Overview citations for this protocol. Each supplement's own profile carries its full source list.
- Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021;384(11):989-1002. PubMed
- Maihemuti A et al. Glucagon Like Peptide-1 Receptor Agonists for Sarcopenia and Muscle Wasting Disorders: A Systematic Review of Efficacy and Mechanisms. Aging Dis. 2025. PubMed
- Barana L et al. Nutrition and Physical Activity in Optimizing Weight Loss and Lean Mass Preservation in the Incretin-Based Medications Era: A Narrative Review. Nutrients. 2025;18(1). PubMed
Common questions.
Quick answers drawn from the stack above.
What is in the GLP-1 Companion Protocol?
The GLP-1 Companion Protocol combines 7 supplements for weight management: Creatine, HMB, Vitamin D3, Methylcobalamin, Calcium, Magnesium Glycinate, and Collagen Peptides. 3 are core; the rest are optional.
How much does the GLP-1 Companion Protocol cost?
NutriStack estimates the GLP-1 Companion Protocol at about $45-75/mo, depending on the forms and brands you choose and whether you run the optional add-ons.
Is the GLP-1 Companion Protocol backed by evidence?
Each supplement in the protocol carries its own evidence tier (2 rated strong here) and links to PubMed-cited sources. NutriStack does not rank or score brands and takes no manufacturer payments; this is an informational reference, not medical advice.
Build it in the app
Run the glp-1 companion protocol in NutriStack.
Add the stack to NutriStack to track timing, screen it for interactions, and see a Stack Score that updates as you tune it.