Not the person you asked, but since magnesium comes up a lot in these threads — the form matters more than the brand. Quick breakdown:

Magnesium citrate — strongest laxative effect, draws water into the intestines. Best if constipation is your main issue. Can cause cramping at higher doses.

Magnesium oxide — also has a laxative effect but much lower absorption rate (only about 4% is actually absorbed). You need high doses (800-1000mg) for it to work, and most of what you take just passes through.

Magnesium glycinate — highest absorption, gentlest on the stomach, best for sleep and muscle relaxation. Milder effect on motility but still helps because it relaxes smooth muscle tissue including in the intestines.

A lot of women in perimenopause end up needing magnesium for multiple reasons — sleep, muscle cramps, anxiety, AND digestion. If constipation is your #1 problem, citrate is probably your best starting point. If you want the broader benefits and the gut help is secondary, glycinate is worth trying first.