Muscle Cramps on Wegovy? It’s Probably Your Electrolytes - Here’s the Fix

You started your GLP-1 medication a few weeks ago. Your appetite is lower, the weight is coming off, and things seem to be working well. Then the muscle cramps start.

Your calves tighten at night. Your feet cramp when you stretch. Your hands feel weak or tense. You look up side effects and barely see anyone talking about it.

So what’s actually causing this and and what can you do about it?

Why GLP-1 Medications Cause Muscle Cramps

Muscle cramps on Ozempic, Wegovy, or Mounjaro are not a listed primary side effect, which is partly why so many users are caught off guard. But they’re actually pretty common.

In most cases, the issue comes down to electrolytes.

GLP-1 medications can lower the minerals your muscles need to work properly, especially sodium, potassium, and magnesium.

Sodium natriuresis: GLP-1s stimulate the kidneys to excrete more sodium in urine. This is a real, documented pharmacological effect. When sodium drops, the fluid balance your muscles depend on is disrupted.

Reduced food intake sodium, potassium, and magnesium all come primarily from food. When your appetite drops by 40–60% and you eat significantly less, you're also consuming far fewer of these minerals. The medication solves one problem (overeating) while creating another (under-nourishment).

GI side effects compounding the loss: Nausea, vomiting, and diarrhoea are common in GLP-1 users, particularly early in treatment or after dose increases. Each of these directly depletes electrolytes faster than you can replace them through diet alone.

Reduced thirst: GLP-1 medications blunt not just hunger but thirst signals. Many users drink significantly less fluid than before, compounding the dehydration and electrolyte depletion picture.

The result is that the specific minerals your muscles need to function are in shorter supply precisely when the medication is working hardest.

The Three Minerals Behind Your Cramps

Magnesium is the most commonly implicated mineral in muscle cramps — and one of the most commonly deficient in GLP-1 users. Magnesium regulates the calcium channels in muscle fibres that control contraction and relaxation. When magnesium is low, muscles can't fully relax after contracting, leading to sustained cramping. Night-time calf cramps in particular are strongly associated with magnesium deficiency.

Potassium works alongside sodium to regulate electrical signalling in muscle and nerve cells. Low potassium can cause muscle cramps and unexpected fatigue. Many GLP-1 users are eating far less fruit, vegetables, and legumes - the primary dietary potassium sources.

Sodium is the master electrolyte for fluid balance. When sodium gets too low, muscles can cramp more easily. This can happen from eating less, drinking lots of plain water without electrolytes and losing sodium through sweat or digestion.

How to Know If Electrolytes Are the Cause

Electrolyte-related cramps usually follow a pattern:

• Calf cramps at night
• Foot cramps when stretching
• Tightness in the hands or forearms
• Cramps after exercise or walking
• Fatigue, headaches, dizziness, or constipation alongside the cramps

If symptoms become severe, especially heart palpitations, confusion, or serious weakness, speak to a doctor.

A blood panel can help check electrolyte levels, although magnesium deficiencies don’t always show clearly on standard labs. Ask specifically about RBC magnesium if available.

The Fix: A Practical Electrolyte Protocol

Step 1: Stop relying on plain water alone. Plain water without electrolytes dilutes your already-depleted sodium further. Add an electrolyte mix or sachet to your water, particularly in the morning and after any activity. Look for products containing sodium (300–500mg per serving), potassium (200–400mg), and magnesium (200-400mg).

Step 2: Add magnesium supplementation. Magnesium glycinate or magnesium citrate (both well-absorbed forms) are useful additions for GLP-1 users experiencing cramps or poor sleep. A typical starting dose is 200 to 400mg taken in the evening.

Step 3: Eat potassium-rich foods intentionally. Bananas, avocado, sweet potato, white potato (with skin), tomatoes, beans, and lentils are all excellent potassium sources. These foods also happen to be GLP-1 friendly as they are low in fat and moderate in fiber.

Step 4: Don't cut salt dramatically. GLP-1 medications increase fluid and sodium loss through a process called natriuresis. Because of this, aggressively cutting salt while eating significantly less can sometimes worsen electrolyte imbalance, contributing to fatigue, dizziness, headaches, or muscle cramps.

For many GLP-1 users, some sodium in meals is not the enemy. It’s an essential electrolyte the body may already be losing more rapidly than usual.

When Will the Cramps Stop?

A lot of people notice muscle cramps most during the first few weeks on a GLP-1, or right after increasing their dose. That’s usually when fluid and electrolyte changes hit hardest before the body has fully adjusted. In many cases, cramps get noticeably better within a few weeks once hydration and electrolyte intake become more consistent.

If the cramps keep happening even after improving fluids and electrolytes, it may be worth looking into other possible causes too. Low vitamin D, thyroid issues, and some medications (especially diuretics or blood pressure medications) can also play a role.

Summary

Most muscle cramps on a GLP-1 aren’t actually caused by the medication itself. They’re usually caused by what happens around it: eating less, losing more sodium and fluids, and sometimes drinking tons of plain water without replacing electrolytes.

The good news is that the solution is usually pretty practical. Focus on electrolytes, magnesium, potassium-rich foods, and balanced hydration instead of only drinking plain water all day.

That’s why many people add a daily electrolyte routine alongside their GLP-1 protocol. Maeva’s Probiotic Electrolyte combines sodium, potassium, and magnesium in a convenient daily hydration formula designed to help support energy, hydration, and muscle function when you’re eating less.

Your muscles rely on minerals to contract and relax properly. When those mineral levels start to drop, cramps can show up fast.

References

1. Crintea IN, Cindrea AC, Mederle OA, Trebuian CI, Timar R. Electrolyte Imbalances and Metabolic Emergencies in Obesity: Mechanisms and Clinical Implications. Diseases. 2025 Feb 24;13(3):69. doi: 10.3390/diseases13030069. PMID: 40136609; PMCID: PMC11941549.
2. McKay NJ, Kanoski SE, Hayes MR, Daniels D. Glucagon-like peptide-1 receptor agonists suppress water intake independent of effects on food intake. Am J Physiol Regul Integr Comp Physiol. 2011 Dec;301(6):R1755-64. doi: 10.1152/ajpregu.00472.2011. Epub 2011 Oct 5. PMID: 21975647; PMCID: PMC3233845.