What supplements should I take on a GLP-1? A simple daily stack

The case for supplements on a GLP-1 medication comes down to one core problem: you're eating far less than before, which means you're getting far fewer nutrients, and you're losing weight faster than your body was designed to handle. Three categories of supplementation have real evidence behind them for this situation: protein to protect muscle, creatine to support muscle function, and targeted micronutrients to fill the gaps a small-volume diet inevitably leaves.

The core problem: less food means less of everything

When tirzepatide or semaglutide reduces your appetite by 30-50%, the benefit is obvious, you eat less, you lose weight. The less obvious consequence is that you also get less protein, fewer electrolytes, lower magnesium, reduced B vitamins, less fiber, and fewer omega-3 fatty acids. Your body's needs for most of these don't decrease just because your appetite did.

The STEP 1 DXA substudy (Wilding et al., 2021, PMC8089287) found approximately 40% of weight lost on semaglutide was lean mass. The SURMOUNT-1 DXA substudy (PubMed 39996356) found approximately 25% of weight lost on tirzepatide was lean mass. That's the target the supplement strategy aims at: getting the fat loss without losing as much muscle and without developing significant nutritional gaps.

The daily stack: what we'd actually take

What to prioritize if you can't do everything at once

1. Protein first. If you're choosing one thing, choose protein. Getting 1.2-1.6 g per kg of bodyweight daily is the intervention with the most direct impact on lean mass preservation. A whey protein isolate makes this achievable even with poor appetite.
2. Creatine second. The Chilibeck et al. 2017 meta-analysis (PMC5679696) gives creatine the strongest RCT backing for lean tissue support in adults. At 3-5 g/day, it's inexpensive and simple.
3. Micronutrients third. A complete multivitamin with magnesium glycinate covers most of the remaining nutritional gaps without requiring you to manage 6 separate products.

What the stack is not

These are not weight loss accelerants. They won't make tirzepatide or semaglutide more effective at reducing body weight. They exist to improve the quality of the weight you're losing (more fat, less muscle) and to maintain the nutritional baseline that keeps you feeling functional during a period of significant metabolic change.

None of these supplements replace resistance training. The research on creatine, protein, and lean mass consistently involves exercise as a component. If you're not doing any resistance training, adding supplements helps less and starting a basic training routine helps more.

A note on GI side effects and supplement timing

GLP-1 medications are associated with nausea, constipation, and other GI symptoms (the 2025 network meta-analysis in Frontiers in Pharmacology, PMC12491879, found nausea rates of 21.49%). Taking supplements on an empty stomach can worsen nausea for some people. Taking everything with or just after a small meal tends to improve tolerance. If nausea is significant, protein shakes at room temperature or slightly diluted may sit better than thick, cold shakes.

Where Anchor fits

The GLP-1 Companion Bundle from Anchor combines the core products for this stack, protein, creatine, and micronutrient support, in a format designed specifically for people on GLP-1 therapy. Rather than sourcing each product separately, the bundle is one decision. It covers the three pillars: protein for muscle, creatine for muscle function, and targeted micronutrients for the nutritional gaps that restricted eating creates. Browse the GLP-1 Essentials collection for individual products if you prefer to build your own stack.

Frequently asked questions

Do I need all of these supplements, or just some?

You don't need all of them, and more is not always better. Protein and creatine have the strongest research basis for the GLP-1 muscle-preservation problem. Magnesium is a practical add if you're experiencing sleep issues or cramping. Omega-3 and multivitamin are reasonable gap-fillers at restricted caloric intake. Start with protein and creatine and add from there based on what you're actually experiencing.

Can I take all of these at once?

Yes, in the sense that there are no known interactions between these supplements. As a practical matter, taking everything at breakfast with food is a reasonable approach, it ensures you don't forget anything and spreads the load on your digestive system. Some people prefer to split: protein and creatine in the morning, magnesium at night.

Are there supplements to avoid on a GLP-1?

There's no category of common supplement with a well-documented dangerous interaction with GLP-1 medications. However, fat-soluble vitamins (A, D, E, K) in very high doses deserve caution on any restricted diet, and stimulant-heavy pre-workouts may interact poorly with nausea. Always tell your prescribing doctor what you're taking.

How long do I need to take these?

As long as you're on a GLP-1 medication and eating significantly below your normal intake, the rationale for protein, creatine, and micronutrient support remains. If you eventually eat a full and varied diet at maintenance calories, you may not need the same stack. But during active weight loss on a GLP-1, the case for supplementation is ongoing.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Talk to your doctor before starting any supplement, especially while on prescription medication.

Written by the Anchor team. Reviewed for accuracy against the primary sources linked above. Last updated September 3, 2026.