Skip to content

Independent GLP-1 journalism

On The Jab

The best supplements for Zepbound and Mounjaro — what a 20% weight loss actually demands

Tirzepatide takes off more weight than any injectable before it, and the supplement question changes with the magnitude. When a fifth of your body is leaving, what you protect matters more than what you optimise.

NR

Dr. Nick Robertson

Founder & Editor

Published
Reading time
2 min read
Medically reviewed
Clinically reviewed

Tirzepatide is the most effective weight-loss drug currently licensed, and that is precisely why the supplement question is different here.

Why magnitude changes the answer

SURMOUNT-1 reported mean weight loss of 20.9% at the top dose. STEP 1, on semaglutide, reported 14.9%.

Both are remarkable. But a fifth of body weight leaving in a year means proportionally more lean tissue at risk, and lean tissue is the part you cannot get back easily once the drug has done its work.

Ranked · supplements for tirzepatide users

How this was ordered: Weighted for the magnitude of loss tirzepatide produces — a mean 20.9% of body weight in SURMOUNT-1, which puts more lean tissue at risk than semaglutide does. Lean mass protection ranks above everything else, then hydration, then fibre, then micronutrient cover.

#ProductKey specPriceBest for
1GLP-1 FoundationMinome5,000 mg creatine + 1,000 mg sodium electrolytes$39.99/mo subThe steepest loss curve in the category
2Gold Standard 100% WheyOptimum Nutrition24 g protein per scoop~$1.10/serving (~$33/mo)Anyone under 1.2 g/kg protein
3Psyllium huskMetamucil / generic~3 g soluble fibre~$10–15/moConstipation, which arrives with the dose increases
4Basic Nutrients 2/DayThorneComprehensive multivitamin · NSF Certified for Sport~$36/moIntake that has collapsed below 1,200 kcal
5GLP-1 CompanionMinome40 B CFU · 4 named strains + FOS$39.99/mo subOngoing gut comfort rather than rescue
  1. 1. GLP-1 Foundation

    Tirzepatide is the most effective agent on the market and therefore the one that most deserves a deliberate lean-mass strategy. A full clinical creatine dose is the best-evidenced supplement for holding strength through a deficit, and the electrolyte load underneath it addresses the dehydration that makes training impossible in the titration weeks.

    Against it No NSF or Informed Sport certification, and roughly triple the price of plain creatine monohydrate if hydration is not a problem for you.

  2. 2. Gold Standard 100% Whey

    On the 10 and 15 mg doses, appetite suppression is severe enough that the protein target becomes a genuine logistics problem. Liquid protein is the workaround, and this is the cheapest credible version of it.

    Against it Competes for the little appetite you have, and whey sits heavily in a stomach already emptying slowly. Sip over an hour rather than downing it.

  3. 3. Psyllium husk

    Cheap, well evidenced, and the correct first move against the constipation that tracks each titration step. Gel-forming rather than fermentable, so less gas than inulin.

    Against it Needs a full glass of water, which is a real ask when fluid intake has already fallen.

  4. 4. Basic Nutrients 2/Day

    When the plate halves, the micronutrient envelope halves with it. This is a well-formulated, independently certified multivitamin rather than a GLP-1-branded one at twice the price.

    Against it Cheaper pharmacy multivitamins cover most of the same ground for under ten dollars. You are paying for form quality and certification.

  5. 5. GLP-1 Companion

    A well-specified daily synbiotic with strains named to the designation, sensible as maintenance once the acute constipation is handled.

    Against it Fifth because it is the least urgent purchase here. Fibre and fluid do more, sooner, for less money.

Prices checked September 2026 and change often. No link on this page is an affiliate link, and no brand listed has paid for, reviewed, or been shown this ranking before publication.

The dose-increase pattern nobody warns you about

Most people find that side effects do not arrive smoothly. They arrive in steps, three to five days after each titration.

That pattern is worth planning around. Constipation and dehydration cluster in the week after an increase, which is exactly when fibre and fluid matter most and exactly when appetite is at its lowest.

What not to buy

Anything marketed as raising your natural GLP-1. Tirzepatide is a dual GIP and GLP-1 receptor agonist at a therapeutic dose. A botanical extract is not a meaningful addition to that.

Common questions

What supplements should I take on Zepbound or Mounjaro?
Creatine monohydrate at 5 g daily and enough protein come first, because tirzepatide produces the largest weight loss of any current injectable and lean tissue is what you are trying to keep. Add electrolytes if you have cramps or light-headedness, psyllium for constipation, and a multivitamin if your intake has dropped very low.
Do tirzepatide users need different supplements than semaglutide users?
The list is the same; the emphasis differs. Tirzepatide produced a mean 20.9% weight loss in SURMOUNT-1 against 14.9% for semaglutide in STEP 1, so there is proportionally more lean mass at stake and a stronger case for prioritising protein and creatine from the start.
Does Mounjaro cause muscle loss?
Some lean mass is lost with any rapid weight loss, and body composition substudies suggest roughly a quarter to 40% of total loss is lean tissue. That proportion is not fixed — resistance training and adequate protein meaningfully improve it.
When should I start taking supplements on tirzepatide?
Creatine and protein from the beginning, because lean mass is easier to keep than to rebuild. Everything else is best added in response to a symptom you actually have rather than bought preemptively.

Sources

  1. 01

    Jastreboff AM, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387:205-216.

  2. 02

    Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). N Engl J Med. 2021;384:989-1002.

  3. 03

    Kreider RB, et al. ISSN position stand: safety and efficacy of creatine supplementation in exercise, sport, and medicine. J Int Soc Sports Nutr. 2017;14:18.

  4. 04

    Cava E, Yeat NC, Mittendorfer B. Preserving Healthy Muscle during Weight Loss. Adv Nutr. 2017;8:511-519.

Editorial standards

Written by Dr. Nick Robertson, MD. Clinical content last checked September 8, 2026. On The Jab takes no money from pharmaceutical companies, telehealth platforms or compounders, and uses no affiliate links. Read our policy.

This article is journalism and general education, not medical advice. Talk to your own clinician before changing any treatment.

The Sunday Dispatch

Get the next one in your inbox.

One email a week from Dr. Robertson. Free, and it stays free.

Keep reading

Guide//5 min

Sulfur burps on a GLP-1

The rotten-egg burp is one of the most reliably reported side effects on tirzepatide and one of the least discussed in clinic, largely because nobody wants to be the person raising it.

Guide//5 min

Constipation on a GLP-1

Nausea gets the attention because it arrives first and loudly. Constipation arrives in week three, never fully resolves for some people, and is the thing they eventually stop over.

Guide//5 min

Teeth and dental work

Repeated vomiting erodes enamel permanently, reflux does it more quietly, and any dental procedure involving sedation now needs the same conversation as surgery. None of this is on the leaflet.

The book · 14 chapters

The GLP-1 Handbook

Everything I tell my own patients before their first injection. 214 pages of what actually matters in the first year — dosing, side effects, food, muscle, cost, and the part nobody prepares you for: maintenance.

$4Less than your morning coffee.
Read the first chapter

Priced at four dollars because it should be affordable to everyone taking these drugs — not because it's worth four dollars. No upsell, no course, no supplement line.