EverStrong

Guide

Fatigue on compounded semaglutide or tirzepatide: why you are flat and what actually lifts it

Fatigue on compounded semaglutide or tirzepatide usually comes from one of four places: eating too little total food, eating too little protein, low iron or another deficiency, or dehydration and low sodium. The first two you can test this week by adding food. The third needs a blood test with your prescriber. Fatigue that arrives with falling strength is the one we treat as a muscle problem until proved otherwise.

Your number, before anything else

Protein is what decides whether the weight you lose is fat or muscle. Work your number out once and we will keep it with you on every page here. No account, no email.

Saved in this browser only. Your dose and how you feel on compounded semaglutide or tirzepatide stay between you and your prescriber.

What to do this week about the tiredness

Compounded semaglutide or tirzepatide produces the same low-intake fatigue as the branded versions. Because product strength and the step-up schedule vary between pharmacies, tell your prescriber how much you are actually eating when you raise it.

  1. Log three honest days

    Everything, including the mouthful you did not count. Most people we coach are 300 to 500 calories (1,250 to 2,100 kJ) lower than they guessed. If the total is under about 1,000 calories (4,200 kJ), that is your answer before you look anywhere else.

  2. Get protein to the floor, then add one carbohydrate meal

    1.2 g per kg of goal weight (0.55 g per lb) as the minimum. For a 70 kg (154 lb) goal, 84 g a day. Then put some carbohydrate back around your strength session: oats, rice, potato, fruit. Low-carbohydrate plus low-calorie plus a GLP-1 is the recipe for feeling wrung out.

  3. Fix the fluid and the salt

    Aim for around 2 litres (68 fl oz) a day and stop avoiding salt. Light-headed on standing is usually fluid and sodium, not the medication itself, though tell your prescriber if it persists.

  4. Run the strength test before you blame the medication

    30-second sit-to-stand, or goblet squat reps at a fixed weight. If that number is falling week on week, the fatigue is muscle, and protein plus two 30-minute sessions is the fix rather than more rest.

  5. Confirm what you are actually taking

    Compounded doses are not standardised, so bring the exact product and strength to your prescriber when you raise fatigue. Meanwhile, log three days of food, because low intake explains most of it.

Four reasons you are flat, in the order worth checking

The first is simply not enough food. On compounded semaglutide or tirzepatide it is common to drift to 700 or 800 calories (2,900 to 3,350 kJ) a day without deciding to, because hunger is not there to argue. Fat loss runs fine on a deficit; it does not run well on almost nothing, and the tiredness is the first thing you notice. Compounded products behave like the branded versions on appetite, but because doses vary, the pattern you read about online may not match yours. Track what you actually eat rather than what you expect to eat.

The second is protein, and it is the one that costs you. Pooled across 20 randomised trials, the lean share of weight lost was 35.2% on semaglutide and 25.4% on tirzepatide, against 26.2% when the same weight came off by diet alone, and 17.5% when resistance training was added. Losing muscle means less tissue doing the work of moving you around, so ordinary things start to feel heavy. The third and fourth are iron and fluid: low iron is common in women over 45 and causes exactly this, and low intake means low water and low sodium, which flattens you before lunch.

A day built for energy, not just protein

  • Breakfast: 2 eggs on wholegrain toast with butter, about 20 g protein and real carbohydrate
  • Mid-morning: 250 ml (8.5 fl oz) milk with a scoop of protein powder, about 30 g
  • Lunch: 120 g (4 oz) chicken with rice and vegetables, about 38 g
  • Dinner: 120 g (4 oz) salmon or lean mince with potato, about 32 g, plus a glass of water and salt on the food

Around 120 g of protein and roughly 1,400 calories (5,850 kJ). If you have been living on 800 calories (3,350 kJ), this is the week to find out whether the tiredness was the medication or the intake.

Work out your own target on Compounded semaglutide or tirzepatide

Three numbers, every Sunday

Tiredness is a feeling and feelings move around. These three tell you what is behind it.

  1. One strength test, same way every week

    Goblet squat reps at a fixed weight, push-ups, or the 30-second sit-to-stand for beginners. Fat loss does not make you weaker, so a number that drops three or four weeks running is a real signal, and it is fixable. It measures what you can do, not how much muscle you have.

  2. Average protein a day, whole week

    Not your best day. 1.2 to 1.6 g per kg of goal body weight (0.55 to 0.7 g per lb), floor 1.2, protein first at every meal.

  3. Upper arm tape, same spot, relaxed

    Centimetres or inches. The waist shrinks whatever you do; if the arm shrinks as fast, that is muscle. Weight is number four, same day and time. The scale tells you what you lost. These tell you what you kept.

Worth a conversation with your prescriber

  • Fatigue that does not lift after two weeks of eating properly, or that is getting worse
  • Fatigue with breathlessness, a racing heart, dizziness, or fainting
  • Fatigue alongside hair shedding, feeling cold, dry skin or constipation, which is worth a thyroid and iron test, and a B12 test if you have had bariatric surgery

Dose and timing on compounded semaglutide or tirzepatide are your prescriber's decisions; we coach the food and the strength.

Free, one page

Forty foods, ranked by protein per bite

The hard part is not knowing you need protein on Compounded semaglutide or tirzepatide, it is hitting the number on a day when food is the last thing you want. One page, grams and ounces, what a real serve looks like, and the first-bite rule for when appetite is gone. Print it and put it on the fridge.

Then five short emails over five days on keeping muscle while the weight comes off, and a short note every fortnight after that if you want it. One click to stop, any time.

Sent. Check your inbox in the next minute or two, and look in junk if it is not there.

Questions people ask

Is fatigue a side effect of compounded semaglutide or tirzepatide?

Tiredness is commonly reported, particularly in the first weeks and after a dose step. In the people we coach it usually tracks intake rather than the medication itself, which is why the three-day food log is the first thing we ask for.

How long does the tiredness last on compounded semaglutide or tirzepatide?

When it is the dose step, most people describe it settling within one to two weeks. When it is running on 800 calories (3,350 kJ) and 50 g of protein, it does not settle at all until the food changes.

Why do I have no energy on compounded semaglutide?

The same reasons as the branded versions: too little food, too little protein, too little fluid, or a deficiency. Work through those with a food log and a blood test rather than assuming it is the product.

Where these numbers come from

Four things cause this. Two you can change this week, one needs a blood test, and one is muscle, which is what the last line is about.

Vitamin D, B12, iron studies, folate, zinc and thiamine are the markers this literature suggests watching. Ask your prescriber whether they are worth checking for you; we do not order or interpret bloods. Arslan S, Clinical Nutrition ESPEN 2026

Guideline-informed protein targets during this kind of weight loss start at 1.2 g per kg of body weight a day (0.55 g per lb). Arslan S, Clinical Nutrition ESPEN 2026

In 191 older adults, higher protein was associated with more preserved lean tissue but not with better grip strength, walking speed or chair-stand scores. Protein looks after the material. Training is what turns it into function. Eglseer D et al, Nutrition Journal 2026

The papers these numbers come from

  • Arslan S. Medical nutrition in the glucagon-like peptide-1 (GLP-1) era: Protein strategies, micronutrient monitoring, and lean mass preservation. Clinical Nutrition ESPEN, 2026. Narrative review, guideline-informed targets. doi:10.1016/j.clnesp.2026.103305
  • Eglseer D, Reiter L, Schoufour JD, et al. Is higher protein intake during weight loss interventions in older adults associated with improved outcomes? A secondary data analysis of three randomised controlled trials. Nutrition Journal, 2026. 191 adults, mean age 65.1 years. doi:10.1186/s12937-025-01279-2
  • Eisa N, Barood O. Lean Mass Changes With Incretin Therapy Versus Lifestyle Intervention: A Systematic Review and Meta-Analysis of Randomised Controlled Trials. Diabetes, Obesity and Metabolism, 2026. 20 randomised controlled trials, 15,782 participants. doi:10.1111/dom.70666

Last reviewed 18 September 2026. We update these figures when a larger or better study replaces them, and we say what changed. How we handle evidence.

The Keep Muscle Kit

The whole system for Compounded semaglutide or tirzepatide, in five PDFs

The workbook, Sunday numbers tracker, 2-day strength plan, injection-day card, and meal plans at 100, 120 and 140 g protein. Instant download.

Get the Kit

A$47 / US$29 / £23, one payment.

Related

All guides, by medication

EverStrong provides nutrition and strength coaching and education. It is not medical advice and does not replace your prescribing doctor. Consult your doctor before starting a new exercise or nutrition plan, especially with a heart, kidney, liver or metabolic condition, if pregnant, or with a history of disordered eating.