Magnesium Types & Your Hormones

You have probably heard that magnesium is good for your hormones. And it is. But here is where most advice stops short: there are at least seven distinct forms of magnesium on the market, and they do not all do the same thing. Taking the wrong type for your goals is a bit like using a flathead screwdriver on a Phillips screw. It might work a little, but not nearly as well as the right tool would.

If you have ever wondered why your magnesium supplement does not seem to touch your PMS, or why one form makes you rush to the bathroom while another makes you sleep like a rock, this guide is for you. We are going to break down the key forms of magnesium, what each one does in the body, and how to use them strategically across your cycle.

Why Magnesium Matters So Much for Hormones

Magnesium is involved in over 300 enzymatic reactions in the human body, including many that directly regulate sex hormones, stress hormones, and neurotransmitters. It plays a central role in cortisol regulation, insulin sensitivity, progesterone synthesis, and the production of mood-stabilising chemicals like serotonin and GABA.

Research consistently shows that women with PMS tend to have lower red blood cell magnesium levels than those without symptoms. A review published by the National Institutes of Health Office of Dietary Supplements highlights magnesium's broad role in muscle function, nerve transmission, and blood glucose regulation - all of which intersect with hormonal health in meaningful ways.

Across your cycle, magnesium needs and tolerances actually shift. During the luteal phase (after ovulation, before your period), progesterone rises and intracellular magnesium tends to drop. This is one reason why PMS symptoms often cluster in this window: lower magnesium means more muscle tension, poorer sleep, heightened anxiety, and more severe cramps.

"Magnesium deficiency is one of the most underdiagnosed issues in women's hormonal health. Standard blood tests measure serum magnesium, which only reflects about 1% of the body's total magnesium. A woman can be significantly depleted and still show a 'normal' lab result."

- Dr. Lara Briden, ND, Naturopathic Doctor and Author, Period Repair Manual

The Main Types of Magnesium: What Makes Each One Different

The form of magnesium refers to what it is bound to. This affects how well it is absorbed, where it goes in the body, and what symptoms it is best suited to address.

Magnesium Glycinate

This is magnesium bound to glycine, an amino acid with its own calming properties. Magnesium glycinate is considered the gold standard for hormonal support. It is highly bioavailable, meaning the body absorbs it efficiently, and it is gentle on the digestive system. The glycine component supports GABA receptors in the brain, which helps to explain why this form is especially effective for anxiety, sleep disruption, and the emotional turbulence many women experience in the luteal phase.

Best for: PMS mood symptoms, luteal phase anxiety, sleep support, general daily magnesium repletion.

Magnesium Malate

Magnesium malate is bound to malic acid, a compound involved in energy production inside the mitochondria. This form tends to be more energising than sedating, which makes it better suited to the follicular and ovulatory phases of the cycle when energy is rising and you want to support performance without disrupting sleep. Women with fibromyalgia or chronic fatigue often find this form particularly helpful.

Best for: Daytime energy, muscle recovery, follicular and ovulatory phases.

Magnesium Citrate

One of the most widely available forms, magnesium citrate is bound to citric acid. It has reasonable bioavailability and a mild laxative effect at higher doses, which makes it a common recommendation for constipation. This laxative effect is less desirable when you are looking for hormonal support specifically, though it can be helpful during the menstrual phase when digestive sluggishness is common.

Best for: Constipation relief, budget-friendly general supplementation, menstrual phase digestive support.

Magnesium Threonate

This is the only form of magnesium that has been shown to cross the blood-brain barrier effectively. Developed by researchers at MIT, magnesium threonate is designed to raise magnesium levels in the brain specifically, which has implications for cognitive function, memory, and mood. A study in the journal Neuron found that magnesium threonate improved synaptic density and cognitive performance in animal models, with human trials suggesting benefits for brain fog and memory.

For women who experience significant brain fog or cognitive dips in the luteal phase, this form is worth considering.

Best for: Brain fog, cognitive support, mood regulation, late luteal phase mental clarity.

Magnesium Taurate

Magnesium taurate combines magnesium with taurine, an amino acid that supports cardiovascular health and nervous system regulation. This form is particularly relevant for women who experience heart palpitations during the premenstrual phase (a surprisingly common but underreported symptom), as well as those managing blood pressure or blood sugar irregularities.

Best for: Hormonal palpitations, blood pressure support, blood sugar regulation, nervous system calming.

Magnesium Oxide

You will find this in many cheap, widely available supplements. Magnesium oxide has poor bioavailability - studies suggest only around 4% is absorbed - which means you are largely paying for something your body cannot use. It does have a strong laxative effect, so it shows up in some constipation remedies, but for hormonal purposes it is largely ineffective.

Best for: Not much, when it comes to hormonal health. Worth avoiding in favour of better-absorbed forms.

Magnesium Chloride

This form is commonly found in topical products such as magnesium oil sprays and bath flakes. Transdermal magnesium (absorbed through the skin) is a useful route for those with digestive sensitivity to oral supplementation. Evidence for topical absorption is mixed, but anecdotally many women find magnesium oil applied to the lower abdomen helpful for menstrual cramps and period pain.

Best for: Topical use for cramps, tension, and relaxation.

How to Match Your Magnesium Form to Your Cycle Phase

Rather than picking one form and using it rigidly throughout the month, you can use your cycle as a guide.

Menstrual Phase (Days 1-5)

Cramps, digestive changes, and fatigue are the dominant themes here. Magnesium glycinate taken at night supports sleep and muscle relaxation. If constipation is an issue in the days leading up to your period, magnesium citrate earlier in the day can help move things along. Topical magnesium chloride on the lower abdomen or lower back may offer localised relief.

Follicular Phase (Days 6-13)

Oestrogen is rising, energy is building, and cognitive performance tends to improve. Magnesium malate is a good match here if you want to support energy production and exercise performance. Because sleep tends to be better in this phase, the sedating properties of glycinate are less critical, though you can continue taking it if you are rebuilding your stores after depletion.

Ovulatory Phase (Days 14-16)

Peak oestrogen and a surge of testosterone create the high-energy, socially engaged window of the cycle. Keep supporting your mitochondria with malate if you are training hard. Some women find magnesium helps with ovulation-related cramping (known as mittelschmerz) - glycinate or topical chloride can ease this.

Luteal Phase (Days 17-28)

This is where magnesium really earns its reputation. Progesterone is dominant, magnesium levels fall, and PMS symptoms emerge. This is the phase to prioritise magnesium glycinate in the evening for sleep and anxiety, potentially adding magnesium threonate during the day if brain fog is significant, and magnesium taurate if palpitations or blood sugar swings are issues.

"The luteal phase is a period of increased metabolic demand. Progesterone raises the basal metabolic rate, and this increased cellular activity can deplete magnesium more rapidly. Targeted supplementation during this window can genuinely change a woman's experience of PMS."

- Dr. Stephanie Estima, DC, Doctor of Chiropractic and Women's Health Researcher, Author of The Betty Body

How Much Magnesium Do You Actually Need?

The Recommended Dietary Allowance for magnesium in adult women is 310-320mg per day, rising to 350-360mg during pregnancy. According to national health surveys in the US, the majority of women do not reach this through diet alone. Top dietary sources include dark leafy greens, pumpkin seeds, legumes, dark chocolate, avocado, and whole grains.

Supplemental doses typically range from 200-400mg of elemental magnesium per day. The word "elemental" matters here: a supplement might say 500mg of magnesium glycinate, but the elemental magnesium content (the amount your body actually uses) will be lower. Check the label for elemental magnesium when comparing products.

Taking magnesium with food generally improves absorption and reduces the chance of loose stools. Splitting the dose between morning and evening is a useful strategy in the luteal phase when demand is higher.

Signs You Might Be Deficient

Because standard blood tests do not reliably capture magnesium status, symptoms are often the most useful clue. Common signs of suboptimal magnesium include:

• Muscle cramps and twitching, including eye twitches
• Difficulty falling or staying asleep
• Heightened anxiety or irritability, especially premenstrually
• Sugar and chocolate cravings (chocolate is rich in magnesium)
• Constipation or sluggish digestion
• Headaches or migraines that worsen before your period
• Fatigue that does not resolve with rest
• Heart palpitations

If several of these resonate, it is worth trialling a well-absorbed form of magnesium for at least 8-12 weeks before assessing the results. Magnesium repletion is not overnight work.

Combining Magnesium with Other Nutrients

Magnesium works in close partnership with several other nutrients. Vitamin B6 enhances magnesium absorption and is itself helpful for PMS, which is why many women find a combined B6 and magnesium supplement more effective than either alone. Vitamin D and magnesium are interdependent: magnesium is needed to activate vitamin D, and without adequate magnesium, vitamin D supplementation may not work as expected.

Calcium and magnesium are often discussed together, but they compete for absorption when taken simultaneously. If you take calcium supplements, spacing them apart from your magnesium by a few hours is a practical approach.