March 12, 2026 · By GUUDIES

7 Signs You Might Be Magnesium Deficient (And What to Do About It)

Magnesium deficiency is awkward to diagnose because standard blood tests only measure the 1% of magnesium that's in your blood. The other 99% is in bones and soft tissue, which means you can be functionally deficient and get a perfectly normal result. These are the signs worth paying attention to.

Why Does Magnesium Deficiency Go Undetected So Often?

Because the symptoms are non-specific and doctors rarely test for it properly. Feeling tired, anxious, or sleeping badly isn't something most people bring to a GP as a possible magnesium issue. And even when they do, the serum test often misses it. The result is a lot of people managing symptoms that have a genuinely straightforward nutritional explanation.

1. Muscle Cramps and Twitches

Magnesium regulates muscle contraction and relaxation. When it's low, muscles stay in a partially contracted state. Leg cramps at night, eye twitches, and general muscle tension are among the most reliable physical signs of insufficiency.

2. Poor Sleep Quality

Magnesium activates the GABA receptors that tell your nervous system to slow down at night. Without enough, you struggle to shift from alert to calm. Waking multiple times, difficulty falling asleep, and feeling unrested despite 8 hours are all associated with low magnesium.

3. Anxiety That Feels Physical

Magnesium regulates the HPA axis, the stress response system. Low magnesium means your stress response is more reactive and slower to return to baseline. If everyday stressors feel disproportionately overwhelming, magnesium is worth investigating.

4. Fatigue That Doesn't Improve With Rest

Magnesium is a cofactor in over 300 enzymatic reactions including the ones producing ATP, your cellular energy currency. Without it, energy production is inefficient. You can sleep 8 hours and still feel exhausted.

5. Headaches and Migraines

Magnesium deficiency is one of the most well-established nutritional triggers for migraines. Studies have found significantly lower magnesium levels in people during migraine attacks. Consistent supplementation reduces frequency for many people.

6. Constipation

Magnesium draws water into the bowel and supports smooth muscle function in the intestines. Magnesium citrate in particular is used therapeutically for this reason. Chronic constipation with no obvious dietary cause is worth connecting to magnesium status.

7. Heart Palpitations

Magnesium is essential for electrical stability in heart muscle cells. Low levels can cause palpitations or an uncomfortable awareness of your heartbeat. If this is new or frequent, see your GP, but magnesium is worth checking as part of the picture.

What to Do If You Recognise These Signs

Start with magnesium glycinate or citrate at 200-400mg daily for 4 weeks. Track what changes. Most people notice something within 2-3 weeks. If you notice nothing after a month with a quality form at a proper dose, magnesium probably isn't the primary issue.

Pair it with B6. Our DailyGreens contains B6 at 200% NRV precisely because it's required for magnesium to be transported into cells and most people supplementing magnesium separately don't know this. DailyGreens is one of six gummies in the Guudies routine, each targeting a different system so everything works together.