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Nutrients and interactions

Supplements if you take Ozempic, Wegovy or Mounjaro

Semaglutide and tirzepatide sharply cut how much you eat, and in trials a quarter to over a third of the weight lost is lean mass, about the same share as with diet alone. Resistance training lowered that share the most, and adequate protein matters, so muscle support comes first, then constipation, then the micronutrient gaps reviews describe. Picks are ranked by evidence. This page is about nutrients and supporting the drug, not replacing it: never stop or change your dose without your prescriber.

This page covers nutrients and supplement interactions. Never stop or change a prescribed medication without your prescriber, and check any new supplement with your pharmacist.

Evidence last reviewed: October 2026

Top picks

OptionEvidenceBest forThe honest note
Whey Protein Strong evidence hitting protein when appetite is low Protein supplementation adds lean mass and strength during resistance training in a meta-analysis of over 1,800 people, especially near 1.6 g/kg of protein a day. It has not been tested on these drugs specifically, but a shake is an easy way to reach your target when you can only eat small amounts. View
Creatine (monohydrate) Strong evidence with resistance training only Combined with resistance training it adds lean mass compared with placebo, at 3–5 g a day. It has not been tested in GLP-1 users, does little without training, and people with kidney disease should ask a doctor first. View
Psyllium Husk (fiber) Strong evidence constipation on the drug A gel-forming bulk laxative with consistent trial support for chronic constipation, at 5–10 g a day with plenty of water. Start low to limit bloating, and separate it from oral medications by 1–2 hours. View

Solid options

OptionEvidenceBest forThe honest note
Multivitamin Limited evidence covering gaps on low intake These drugs cut energy intake by up to 40%, and a review found more than 60% of users fell short on calcium and iron intake. A standard one-a-day multivitamin cheaply covers common shortfalls; avoid megadose formulas. View

Situational

OptionEvidenceBest forThe honest note
Vitamin D3 Strong evidence if a blood test is low Vitamin D deficiency was the most common abnormality in GLP-1 users, rising from 7.5% at 6 months to 13.6% at 12 months. Supplementation corrects deficiency effectively; 1,000–2,000 IU a day is a common maintenance range. View
Iron Strong evidence confirmed low ferritin only In observational data, GLP-1 users had 26–30% lower ferritin than people on SGLT2 inhibitors. Supplement only after a ferritin test, since iron without a documented deficiency is pointless at best and dangerous at worst. View

Training for this goal

Supplements only help on top of the right training. The evidence-graded base program for this goal:

How to lose fat and keep muscle: what the evidence says

Free base program: 3 lifting days plus cardio and steps

Calorie deficit
Aim to lose about 0.5–1% of body weight per week
Protein
About 1.6–2.4 g/kg per day, spread over 3–5 meals
Lifting
3 full-body sessions per week, 10+ hard sets per muscle per week, 1–3 reps in reserve
Cardio
1 interval session (e.g. 4×4 min hard, 3 min easy) plus 1–2 sessions of 30–45 min steady cardio

See the full program →

Skip, or avoid with this medication

  • GLP-1 Support Formulas Limited evidence

    Some fibers raise GLP-1 slightly, far less than the drugs do, the blends have no trials of their own, and they can reduce absorption of medicines taken at the same time.

  • Berberine Moderate evidence

    Sold as a natural Ozempic, it lowers glucose modestly in small, mostly high-risk-of-bias trials, has no adequately powered weight-loss trial, and interacts with many drugs.

  • Akkermansia Muciniphila Limited evidence

    Its metabolic claims rest on one exploratory trial in 32 people over 3 months, and long-term safety is unknown.

  • Lactobacillus Gasseri Limited evidence

    Its GLP-1 and appetite claims come from rodent and lab work, and the best human weight result was about 1–1.5 kg over 12 weeks.

  • BCAA (Branched-Chain Amino Acids) Limited evidence

    Muscle sparing during dieting has been shown with complete protein, not BCAAs alone, and 25 g of whey already supplies about 5–6 g of BCAAs.

Our verdict

Pair resistance training with enough protein, using whey or another protein powder when appetite is low, and add creatine if you train. Use psyllium for constipation, and ask for vitamin D, iron and B12 checks if you stay on the drug for many months. Skip GLP-1 support blends and berberine sold as a natural alternative; none comes close to the drug.

Key studies