Magnesium and the menstrual cycle

The physiology of menstruation

If no fertilised egg has implanted, the lining of the uterus is broken down. Messenger substances from the prostaglandin group are involved, prompting the uterine muscle to contract. Those contractions are the mechanism behind the cramping character of the symptoms.

The uterus is made of smooth muscle. And magnesium contributes to normal muscle function — one of the authorised health claims. It is via that bridge that the mineral is discussed in connection with the cycle.

What the evidence shows

A double-blind, placebo-controlled study in 60 students with moderate to severe primary dysmenorrhoea compared two magnesium doses (150 and 300 milligrams of magnesium stearate) against placebo. Both doses were associated with a reduction in the menstrual symptoms recorded, the higher dose more markedly so (1).

Two caveats belong with that. First: this is a small study, with 20 participants per group, in a very specific population — students in one hall of residence. Second, and more important for this site: what was studied was oral intake. The finding cannot be transferred to transdermal application, for which no comparable data on this question exist.

What can be said regardless: magnesium requirements are not a fixed quantity and can shift over the cycle. An adequate supply is sensible anyway — that needs no connection to menstruation.

And the other side of it: severe period pain is not automatically normal. Pronounced symptoms can have conditions such as endometriosis behind them, which often goes unrecognised for years. If pain limits your daily life, that belongs in a gynaecological assessment — not in a self-experiment with supplements.

Application through the skin

During menstruation, abdominal symptoms are frequently accompanied by nausea or gastrointestinal complaints. That is the point at which application through the skin becomes practically interesting: it does not involve the digestive tract, whereas oral magnesium itself triggers bloating or diarrhoea in some people.

In practice: apply magnesium oil to the lower abdomen and — if symptoms extend there — to the sacral region, rubbing it in with circular movements and leaving it at least 20 minutes. Alternatively a foot bath with magnesium bath flakes at around 37 degrees Celsius, 15 to 20 minutes. Details are under Application.

Two restrictions on foot baths: graduated hot foot baths are not suitable in cardiovascular disease or with varicose veins. And with known kidney disease, any additional magnesium intake should be discussed with a doctor beforehand.

In context

Magnesium is one element of an adequate nutrient supply, not a remedy for period pain. Application through the skin has the factual advantage of bypassing the digestive tract. What it does not do is replace a diagnosis.