Magnesium Types Explained: Citrate, Glycinate, Chloride, Oxide — Which One and When
The short answer
There's no single "best" magnesium — each form is a trade-off between absorption, gut effect, and purpose. The quick map: glycinate for gentle oral supplementation, citrate when constipation is part of the picture, oxide mostly disappoints, and chloride is the form of choice for topical use.
The four you'll actually encounter
- Magnesium glycinate — magnesium bound to glycine, a calming amino acid. Well absorbed orally, easiest on the stomach, the default recommendation for sleep-focused supplementation. Downside: bulky molecule, so pills are large and you need several.
- Magnesium citrate — well absorbed and inexpensive, but it pulls water into the bowel. That's why it doubles as a constipation remedy — and why it backfires for people with sensitive stomachs.
- Magnesium oxide — the cheapest and most common form in drugstore bottles, with the lowest absorption of the group (often cited around 4%). If a supplement disappointed you, check the label — it was probably oxide.
- Magnesium chloride — highly soluble and the best-studied form for topical delivery; it's what magnesium "oils," bath flakes, and quality creams use. Through skin, it bypasses the gut entirely — no laxative threshold, no stomach upset.
Oral vs. topical: different jobs
Oral forms are the right tool for raising overall magnesium status, especially if a blood test says you're low. Topical chloride is the right tool for a targeted, gut-free nightly ritual — modest systemic absorption (research points to hair follicles, boosted by massage), delivered directly to the calves and shoulders that hold your tension, wrapped in a routine your nervous system learns. Many people sensibly use both.
What to avoid
- Oxide-based products marketed as premium.
- Magnesium "oil" sprays if you have sensitive skin — chloride brine on dry skin stings and itches, which is why most people quit them within a week. A cream buffers the same mineral in a comfortable base.
- Mega-dosing any oral form — the gut sets a hard limit, and it will let you know.
The bottom line
Match the form to the job. For the nightly wind-down and tight-muscle comfort, magnesium chloride in a well-formulated cream is the practical winner — which is exactly what Deep Rest and Deep Recovery are built on. The full ingredient rationale lives on our Science page.