Supplements on GLP-1: What Amy Actually Takes

When your appetite drops on Wegovy, Mounjaro or Ozempic, the calories are not the only thing that falls. Your intake of vitamins and minerals drops in lockstep. Eat 1,000 fewer calories a day and you are also getting far less iron, B12, zinc, magnesium and protein than your body is used to. Micronutrient deficiency on GLP-1 is not a risk, it is close to a certainty if you do nothing about it.

This is the hidden cause behind three of the most common complaints I hear: hair loss, persistent fatigue, and muscle weakness. None of them are the medication damaging you. They are your body running short of the raw materials it needs. Here is exactly what I take, what is worth adding, and what to leave on the shelf.

Section 1: Essential (take these from day one)

These are the non-negotiables. If you do nothing else, do these.

• Vitamin B12. GLP-1 slows gastric emptying and reduces stomach acid, both of which impair B12 absorption. Low B12 causes exactly the fatigue and brain fog people blame on the medication. Vegans and meat-eaters alike should supplement.
• Iron. Especially for women still menstruating. Iron deficiency is the most common driver of fatigue and hair shedding, and it is very easy to fall short when eating less red meat.
• Vitamin D3 with K2. UK deficiency is near-universal from October to April. K2 directs calcium to your bones rather than your arteries. This pairing supports bone density, which matters during rapid weight loss.
• Zinc. Critical for immune function, skin and hormone production. One of the first minerals to fall on a reduced diet.
• Magnesium glycinate. The glycinate form is gentle on the gut and supports sleep and muscle function. Avoid magnesium oxide, which is poorly absorbed and can worsen the gut issues you are already managing.

Simply Supplements cover most of these essentials at honest prices, and DR.VEGAN is excellent if you want clinically formulated, plant-based versions. For superior bioavailability on the methylated B vitamins and magnesium, KIKI Health make whole-food formulations worth the premium.

Section 2: Useful (worth adding)

These are not essential for everyone, but most people on GLP-1 benefit:

• Collagen peptides. Support skin elasticity and muscle integrity during rapid loss. Two to ten grams daily for eight to twelve weeks has real clinical backing for skin.
• Omega-3 (EPA/DHA). Anti-inflammatory and cardiovascular support, relevant given the metabolic changes you are going through.
• Probiotics and prebiotic fibre. Gut side effects are the main reason people quit GLP-1 early. io Gut Health deliver prebiotic fibre in a daily water format that most people find far easier to stick to than capsules.

Section 3: Not worth it

Save your money on these:

• "Fat burner" blends. You are on the most effective appetite and metabolic medication available. Stimulant fat burners add nothing but jitters and wasted cash.
• Appetite suppressants. GLP-1 already does this, comprehensively. Stacking another suppressant on top is pointless and can be unpleasant.
• High-dose vitamin C megadosing. Beyond correcting an actual deficiency, extra vitamin C is simply excreted. A normal multivitamin amount is plenty.

Section 4: Practical tips

• Use gummy formats on nausea days. On days when swallowing capsules feels impossible, Vegums make it easy to keep your essentials going without the gag reflex.
• Time supplements away from your injection. There is no strict rule, but many people find taking supplements with their largest meal sits better than on an empty stomach.
• Split doses if your stomach is sensitive. Half in the morning, half in the evening is gentler than one large dose.

The Bottom Line

The point of supplementing on GLP-1 is not optimisation, it is replacement. You are eating less, so you are absorbing less, so you top up the gaps. Get the five essentials in place, add collagen and a gut support if you can, and skip the marketing-led extras. For the full deep dive, see our supplements on GLP-1 guide and our protein intake guide, which covers the single most important nutrient of all.

If you are still choosing a provider, our clinic comparison flags which UK clinics include nutritional support as standard.