Headaches on GLP-1 (Mounjaro/Wegovy/Ozempic): What Actually Helps (UK)

Affiliate disclosure (UK): This post contains affiliate links. If you buy through them, I may earn a commission at no extra cost to you. I only link to products I’d genuinely consider in a practical routine.

Not medical advice. Always read labels and check interactions. Speak to your GP/pharmacist/clinician if you’re pregnant/breastfeeding, have kidney/heart/liver conditions, have migraines, take prescription medication (especially blood pressure meds, diuretics, thyroid meds, antidepressants, anticoagulants/blood thinners, diabetes meds), or you’re unsure. If headaches are severe, sudden, one-sided with weakness, come with chest pain, confusion, vision changes, fainting, or you can’t keep fluids down, seek urgent medical advice.

Jump to what you need:

Quick answer (60 seconds)
Why GLP-1 headaches happen
Decision flow (what to try first)
Best picks (minimal stack)
Comparison table
What NOT to do
Timeline (3 days / 2 weeks / 30 days)
Objections + safety checks
Related reading
FAQs

If you want to browse my full supplement hub first (guides + product pages):
https://alanspicer.com/best-health-supplements/index.html

If you’re buying from Lily & Loaf, use the code ALAN10 via the official discount page:
https://alanspicer.com/best-health-supplements/lily-and-loaf-discount-code.html

Brand guide:
https://alanspicer.com/best-health-supplements/lily-and-loaf.html

Quick answer (60 seconds)

On GLP-1 meds, headaches are often caused by hydration drift (you eat less… and you often drink less without noticing), low electrolytes (especially if you’re sweating, ill, or your food volume is down), constipation, poor sleep, or caffeine timing. The simplest win is usually: consistent fluids + one daily electrolyte for 3–7 days, then add one targeted support (sleep routine or magnesium) if headaches persist. One change at a time so you can tell what actually worked.

Why headaches can show up on GLP-1 (even when weight loss is “working”)

In my own GLP-1 weight loss journey, the biggest difference wasn’t a massive supplement stack — it was boring consistency.

Lower appetite → lower fluid intake: thirst cues can get weird, and dehydration sneaks up.
Electrolyte drop: eating less often means less sodium/potassium/magnesium coming in.
Constipation + slow gut: pressure, bloating and poor sleep can trigger headaches.
Caffeine + smaller meals: your usual coffee can hit harder, or the “crash” can be worse.
Sleep disruption: reflux, nausea, dose changes, and stress can mess with recovery.

The goal here isn’t “take everything”. It’s fix the biggest lever first, then add one targeted support if needed.

Decision flow: what I’d try first (no overthinking)

If your headache feels like “washed out / flat / dehydrated”

Water habit (big bottle, visible, always with you)
Electrolytes once per day for 3–7 days

If headaches come with cramps, restless evenings, or choppy sleep

Keep the hydration step above
Add magnesium for 2–3 weeks (evening routine)

If headaches come with nausea/reflux or constipation

Hydration + electrolytes first
Then address the root issue (constipation plan or reflux routine)

If you’re mainly indoors (UK winter) and feel generally run-down

Baseline hydration habit
Consider Vitamin D as a seasonal “boring basic” (check suitability)

Best picks (minimal stack) — start with ONE

I’m linking to my hub product pages first (so you can read the notes), then a direct “Buy at Lily & Loaf” link second (affiliate).

1) Electrolyte Drink (fastest test for hydration drift)

Why I’d try it: If you’re headachy, dizzy, crampy, or you feel “flat” — I assume hydration has drifted until proven otherwise. This is the cleanest 3–7 day test.

Buy Electrolyte Drink at Lily & Loaf →

2) Water Bottle (behaviour tool that makes hydration automatic)

Why I’d try it: If you “forget to drink”, supplements won’t save you. A simple bottle you actually use beats willpower.

Buy Water Bottle at Lily & Loaf →

3) Triple Magnesium (cramps, tension, sleep-linked headaches)

Why I’d try it: If headaches track with restless evenings, tension, cramps, or poor sleep, magnesium is usually the first single ingredient I trial. Start low and take with food if sensitive.

Buy Triple Magnesium at Lily & Loaf →

4) Vitamin D3 + K2 (High Strength) (UK winter routine)

Why I’d consider it: If you’re indoors a lot (UK winter especially), vitamin D is one of the few “boring basics” many people consider. Check dose, existing prescriptions, and suitability.

Buy Vitamin D3 + K2 at Lily & Loaf →

Money saver: If you’re ordering, use ALAN10 via the official discount page:
https://alanspicer.com/best-health-supplements/lily-and-loaf-discount-code.html

Comparison table: pick the right option (and don’t stack everything)

If your main issue is…	Start with	Why it’s a sensible first step	Give it a fair test	Hub page
Headaches + dizziness / “washed out” fatigue	Electrolytes	Hydration drift is the most common (and easiest) variable to fix on GLP-1	3–7 days	https://alanspicer.com/best-health-supplements/products/electrolyte-drink.html
“I forget to drink” / I need it to be automatic	Water bottle habit	Behaviour beats willpower. This makes the basic step happen daily	3–7 days	https://alanspicer.com/best-health-supplements/products/water-bottle.html
Headaches + cramps / tension / restless evenings	Magnesium	Often supports an evening routine and muscle comfort (sleep-linked headaches)	2–3 weeks	https://alanspicer.com/best-health-supplements/products/triple-magnesium.html
Winter fatigue / indoor life (UK)	Vitamin D3 + K2	Common seasonal “boring basic” consideration (check suitability/dose)	4–8 weeks	https://alanspicer.com/best-health-supplements/products/vitamin-d3-k2-high-strength.html

Rule of thumb: start with one change. If you start electrolytes, magnesium, and vitamin D all at once and you feel better… you’ll never know what actually helped.

What NOT to do (trust booster)

Don’t stack five new supplements on day one. You’ll never identify the cause if headaches worsen.
Don’t “treat” headaches by skipping food entirely. Under-eating can amplify fatigue and make headaches worse.
Don’t go aggressive with caffeine. If you’re eating less, your usual coffee can hit harder (and crash harder).
Don’t ignore constipation. Gut slowdown can wreck sleep and trigger headaches.
Don’t push through warning signs. Severe/sudden headaches or neurological symptoms need medical attention.

Timeline: what to expect (3 days / 2 weeks / 30 days)

First 3 days: If dehydration/electrolytes are the issue, you may notice fewer “washed out” headaches and less dizziness once fluids are consistent.

By 2 weeks: If sleep/tension is involved, magnesium and a calmer evening routine often take a little time. This is where you start noticing steadier mornings.

By 30 days: You’ll know what’s worth keeping. The goal is a routine that feels boring — because boring is repeatable.

Objections + safety checks (straight answers)

“Isn’t this expensive?”

It can be — which is why I prefer one targeted trial based on your biggest symptom. Most people don’t need a cupboard full of tablets.

“Can electrolytes raise my blood pressure?”

Some electrolyte products contain sodium. If you have hypertension, kidney/heart issues, or you’re on fluid restrictions, check suitability with a clinician.

“What if supplements make nausea worse?”

Keep it simple, take with food where appropriate, and don’t stack lots of new things at once. If nausea is part of your pattern, start here:
https://alanspicer.com/nausea-on-glp1-what-actually-helps-uk/

“When should I stop?”

If anything makes symptoms worse, stop immediately. If there’s no meaningful benefit after a fair trial window, it’s probably not the right fit.

“What about interactions?”

This matters. Minerals can interact with some medications and dosing. If you take prescriptions, a pharmacist can quickly sanity-check your plan.

Calm CTAs (no hype)

If you want to browse all guides + product pages, start here: https://alanspicer.com/best-health-supplements/index.html
If you’re ordering from Lily & Loaf, use ALAN10 via the official discount page: https://alanspicer.com/best-health-supplements/lily-and-loaf-discount-code.html

Hydration & electrolytes (hub guide): https://alanspicer.com/best-health-supplements/best-supplements-for-hydration-electrolytes.html
Tired on GLP-1 (UK): https://alanspicer.com/tired-on-glp1-what-actually-helps-uk/
Sleep on GLP-1 (UK): https://alanspicer.com/sleep-on-glp1-what-actually-helps-uk/
Nausea on GLP-1 (UK): https://alanspicer.com/nausea-on-glp1-what-actually-helps-uk/
Constipation on GLP-1 (UK): https://alanspicer.com/constipation-on-glp1-what-actually-helps-uk/
Hub home: https://alanspicer.com/best-health-supplements/index.html

FAQs

1) Are headaches a common side effect of Mounjaro/Wegovy/Ozempic?

They can be. Often it’s not the medication “directly” — it’s dehydration, low food volume, electrolyte changes, constipation, or sleep disruption that happens alongside GLP-1 weight loss.

2) What’s the fastest thing to try for GLP-1 headaches?

Consistent fluids plus a daily electrolyte for 3–7 days, especially if you feel dizzy, crampy, or “washed out”.

3) Do electrolytes help headaches?

If the headache is linked to hydration drift or low electrolytes, they can help. If the headache is migraine-type or has neurological symptoms, seek medical advice.

4) Can electrolytes affect blood pressure?

They can if the product contains sodium. If you have high blood pressure or kidney/heart issues, check suitability with a clinician.

5) Can magnesium help with headaches?

It can help some people, especially if headaches track with tension, cramps, or poor sleep. Trial it for 2–3 weeks and don’t start multiple new things at once.

6) Why do headaches feel worse after coffee on GLP-1?

If you’re eating less, caffeine can hit harder. You may also be slightly dehydrated, which can make caffeine-related headaches and crashes worse.

7) Could constipation be causing my headaches?

Indirectly, yes — constipation can worsen sleep, increase discomfort, and make you feel generally “off”. Address hydration first, then work on regularity.

8) Should I stop my GLP-1 medication because of headaches?

Don’t change medication without medical advice. If headaches are severe, worsening, or come with red-flag symptoms, speak to a clinician urgently.

9) What’s a minimal, safe GLP-1 “headache routine”?

Water habit + one daily electrolyte. Only add magnesium or vitamin D if it matches your situation and you’ve checked suitability.

10) How long should I trial electrolytes?

Usually 3–7 days is enough to notice whether hydration drift was the problem.

11) How long should I trial magnesium?

Give it 2–3 weeks of consistency. If you feel worse or get stomach upset, stop and reassess.

12) Where can I browse your full Lily & Loaf picks?

Start here: https://alanspicer.com/best-health-supplements/index.html

13) What’s the easiest way to save money at Lily & Loaf?

Use the code ALAN10 via the official discount page: https://alanspicer.com/best-health-supplements/lily-and-loaf-discount-code.html

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