The Ultimate Nutrition Guide for GLP-1 Medications (Ozempic, Mounjaro, Wegovy & Zepbound, Retatrutide)

GLP-1 medications like Ozempic, Mounjaro, Wegovy and Zepbound are transforming weight management.

But while most conversations focus on appetite suppression and weight loss, far fewer discuss something equally important:

Nutrition.

If you’re eating significantly less — and digesting food more slowly — what happens to your micronutrient intake?

This guide explains:

• How GLP-1 medications affect digestion and absorption

• Which nutrient deficiencies are most common

• Why fatigue, hair loss and dizziness happen

• How to structure supplementation properly

• What to take — and when

How GLP-1 Medications Affect Nutrition

GLP-1 receptor agonists mimic a natural hormone that:

• Reduces appetite

• Slows gastric emptying

• Improves insulin sensitivity

• Increases satiety

That delayed gastric emptying is key.

Food stays in the stomach longer. Appetite drops. Portion sizes shrink. Fat intake often decreases.

While beneficial for weight loss, this can reduce overall micronutrient density — particularly if:

• Meals become smaller and less varied

• Protein intake drops

• Dietary fat decreases (affecting fat-soluble vitamin absorption)

• Nausea limits food choices

Over time, this can increase the risk of specific deficiencies.

For a full breakdown, see:
Nutrient Deficiencies Common on GLP-1 Medications (Mounjaro, Ozempic, Wegovy, Zepbound)

Most Common Nutrient Gaps on GLP-1 Medications

Iron

Lower food intake + reduced red meat consumption = increased anaemia risk.

See:

• Anaemia on Ozempic, Mounjaro or Wegovy?

• Managing Anaemia on GLP-1 Medications

• Taking Iron and Calcium Together? Why Timing Matters

Vitamin B12

B12 absorption depends on stomach acid and intrinsic factor. Reduced intake can compound risk.

See:

• Nutritional Supplementation for Vitamin B12 and Vitamin K2

• How Do We Absorb Vitamins and Minerals?

Magnesium

Lower intake + digestive changes can contribute to:

• Fatigue

• Sleep disruption

• Muscle cramps

Explore:

• Does Mounjaro Cause Fatigue?

• Fatigue on Ozempic, Mounjaro or Wegovy?

• Magnesium Glycinate vs Magnesium Oxide

• Best Magnesium Supplement for Sleep and Recovery

Zinc

Reduced protein intake can reduce zinc status, contributing to:

• Hair thinning

• Immune changes

• Skin issues

See:

• Hair Loss on Ozempic, Mounjaro or Wegovy?

• Why GLP-1 Users Are Losing Hair — and How to Stop It

• Can You Take Zinc and Copper Together?

Fat-Soluble Vitamins (A, D, E, K)

Lower fat intake may affect absorption.

Read:

• Fat-Soluble Vitamins on Ozempic & Mounjaro

• When to Take Vitamin D for Best Absorption

• What Supplement Helps Absorb Vitamin D?

Why Symptoms Like Fatigue & Hair Loss Happen

GLP-1 side effects are often nutritional — not just hormonal.

Fatigue

May be linked to:

• Iron deficiency

• Low B12

• Reduced calorie intake

• Electrolyte imbalance

Explore:

• Managing Tiredness on Ozempic or Mounjaro

• How to Maintain Energy on Mounjaro or Ozempic

• Tired on Ozempic or Mounjaro? How to Boost Energy Naturally

Hair Loss

Often linked to:

• Iron depletion

• Zinc insufficiency

• Protein reduction

See:

• Does Mounjaro Cause Hair Loss?

• Hair Loss on Ozempic, Mounjaro or Wegovy?

• How GLP-1 Medications Affect Hair, Skin & Nails

Dizziness & Headaches

May relate to:

• Electrolytes

• Reduced sodium intake

• Dehydration

Read:

• Dizziness on Mounjaro or Ozempic?

• Getting Headaches on Mounjaro or Ozempic?

• Blood Pressure on GLP-1 Medications

Digestive Issues

Delayed gastric emptying can also contribute to:

• Diarrhoea

• Constipation

• Nausea

See:

• Ozempic & Mounjaro Diarrhoea: Causes and Support

• Sleep Problems on Mounjaro or Ozempic

Should You Take a Multivitamin on GLP-1?

Short answer: often yes.

When food intake decreases, supplementation can act as nutritional insurance.

But not all multivitamins are equal.

Traditional one-a-day formulas often:

• Combine competing minerals (iron + calcium)

• Pair zinc without balancing copper

• Provide low doses

• Ignore nutrient timing

For more on absorption science, read:

• Does the Body Absorb Multivitamins?

• Vitamins You Shouldn’t Take Together

• The Science Behind Nutrient Timing

• Chrononutrition: The Power of Nutrient Timing

Why Nutrient Timing Matters on GLP-1

Because gastric emptying is slowed, absorption dynamics may change.

Consider:

• Iron absorbs best away from calcium

• Fat-soluble vitamins absorb better with dietary fat

• Magnesium may support evening relaxation

• B vitamins are often better tolerated earlier in the day

See:

• Morning vs Evening Supplements

• Best Time to Take Vitamins

• Vitamin Absorption and Coffee

• Impact of Caffeine on Nutrient Absorption

What Supplements Are Most Helpful on GLP-1?

This depends on symptoms and diet, but commonly useful categories include:

• Iron (if clinically indicated)

• Magnesium (especially glycinate for sleep)

• Zinc (balanced with copper)

• Vitamin D3 (with K2 where appropriate)

• A structured multivitamin designed around absorption

Explore:

• Best Supplements to Take with Mounjaro or Ozempic

• Best Multivitamin for Mounjaro & Ozempic Users

• Do You Need a Multivitamin While on GLP-1 Medications?

Can Delayed Gastric Emptying Affect Absorption?

Potentially, yes.

Longer gastric retention may:

• Alter mineral ionisation

• Change timing of small intestinal absorption

• Affect fat-soluble nutrient uptake

This is an emerging area — but it reinforces the importance of:

• Spacing competing nutrients

• Considering dose timing

• Avoiding poorly absorbed forms

For deeper science, see:

• How Do We Absorb Vitamins and Minerals?

• Does Splitting Supplements Improve Absorption?

The Bigger Picture: Weight Loss vs Nutritional Health

GLP-1 medications are powerful tools.

But sustainable health requires:

• Adequate protein

• Micronutrient sufficiency

• Electrolyte balance

• Smart supplementation

• Long-term strategy

Weight loss without nutritional support can compromise:

• Energy

• Muscle mass

• Hair health

• Immune resilience

• Bone health

FAQ: GLP-1 Medications & Nutrition

Do GLP-1 medications cause vitamin deficiencies?

They don’t directly “deplete” vitamins, but reduced intake and dietary changes can increase risk over time.

Should I take a multivitamin on Ozempic or Mounjaro?

If your intake is reduced, supplementation may help support baseline micronutrient needs.

Why does hair fall out on GLP-1 medications?

Often linked to iron deficiency, zinc imbalance, protein reduction, or rapid weight loss.

Does delayed gastric emptying affect nutrient absorption?

It may alter absorption dynamics, especially for minerals and fat-soluble vitamins.

What are the most important nutrients on GLP-1?

Iron, B12, magnesium, zinc, vitamin D and protein are commonly discussed.

We provide a nutrient-by-nutrient risk analysis for GLP-1 users in this pillar article.

Final Thoughts

GLP-1 medications are changing modern medicine.

But appetite suppression should not mean nutritional compromise.

If you’re using Ozempic, Mounjaro, Wegovy, Retatrutide or Zepbound, think beyond weight loss.

Think about:

• Absorption

• Timing

• Mineral balance

• Long-term micronutrient status

Because metabolic health is more than a number on the scale.