Magnesium citrate is one of the best-absorbed, best-value magnesium forms — and its gentle bowel-regularity effect is a feature for many people, not a bug. Our top picks: NOW Magnesium Citrate (best overall), Nutricost (best value), and Pure Encapsulations (best premium).
Our Top 3 Picks at a Glance
- Best Overall: NOW Magnesium Citrate 200mg — 200mg elemental magnesium per tablet from a GMP-certified legacy brand, 250-count bottle
- Best Value: Nutricost Magnesium Citrate 420mg — full 420mg per two-capsule serving, 240 capsules, third-party tested
- Best Premium: Pure Encapsulations Magnesium (Citrate) — hypoallergenic, practitioner-grade citrate with minimal excipients
How We Picked
Magnesium citrate products live or die on three things: the elemental magnesium per serving (the number that matters — not the total compound weight), manufacturing quality (GMP certification and third-party testing), and cost per serving. We also considered capsule vs tablet format and excipient load for sensitive users.
We excluded products that label the compound weight in a way that overstates the elemental dose, blends that dilute citrate with cheaper oxide without clear labeling, and brands without a verifiable quality program. All three picks disclose elemental magnesium clearly.
A. NOW Magnesium Citrate — Best Overall
NOW Magnesium Citrate 200mg
NOW Foods
- 200mg elemental magnesium per tablet
- Large 250-tablet bottle — months of supply
- Family-owned brand with in-house GMP-certified manufacturing
- Simple one-or-two tablet dosing to hit your target
- Vegan, non-GMO formula
- Decades-long track record in quality testing
Why we picked it: NOW hits the sweet spot of trust, dose flexibility, and price. One tablet gives a sensible 200mg; two covers higher needs. NOW's in-house lab testing program is among the most established in the industry, and the 250-count bottle keeps cost per serving low. Best default choice for most people.
B. Nutricost Magnesium Citrate — Best Value
Nutricost Magnesium Citrate 420mg
Nutricost
- 420mg elemental magnesium per two-capsule serving
- 240 capsules — 120 full servings per bottle
- Third-party tested, made in a GMP-compliant facility
- Gluten-free, non-GMO, vegetarian capsules
- Very low cost per serving
- Split the serving for a lighter 210mg dose
Why we picked it: Nutricost delivers the full men's-RDA-level 420mg serving at one of the lowest costs per milligram on Amazon, with third-party testing. Capsules also suit people who dislike large tablets. Best for value shoppers and higher-dose users — start with one capsule if you're new to citrate.
C. Pure Encapsulations Magnesium Citrate — Best Premium
Pure Encapsulations Magnesium (Citrate)
Pure Encapsulations
- Practitioner-grade brand frequently recommended by clinicians
- Hypoallergenic: free of wheat, gluten, egg, artificial colors and sweeteners
- 150mg elemental magnesium per capsule for precise titration
- Minimal excipients for sensitive users
- Rigorous ingredient sourcing and testing standards
- Gentle option for daily long-term use
Why we picked it: Pure Encapsulations is the brand integrative practitioners reach for when a patient needs a clean label — no unnecessary fillers, allergens, or coatings. The smaller 150mg capsules make it easy to fine-tune your dose. Best for sensitive stomachs, allergy-conscious users, and anyone who wants pharmaceutical-style quality control.
Quick Comparison
| Product | Elemental Mg/serving | Format | Count | Best For |
|---|---|---|---|---|
| NOW | 200mg per tablet | Tablet | 250 | Most people |
| Nutricost | 420mg per 2 capsules | Capsule | 240 | Value & higher doses |
| Pure Encapsulations | 150mg per capsule | Capsule | 90 | Sensitive users |
What Magnesium Citrate Is Best For
Citrate is magnesium bound to citric acid, and it solves the biggest problem with cheap magnesium: absorption. Studies comparing forms have repeatedly found citrate is absorbed substantially better than magnesium oxide, the form used in most drugstore multis. That makes citrate a strong everyday choice for topping up intake — roughly half of US adults don't hit the RDA from food — and for supporting muscle function, nerve function, and sleep quality.
Citrate's signature trait is its mild osmotic effect: it draws a little water into the bowel. At normal supplement doses this typically just supports regularity, which is why citrate is the go-to form for people who also deal with occasional constipation. If your gut is sensitive or you want magnesium purely for relaxation and sleep, a gentler chelate like glycinate may fit better — our magnesium glycinate vs citrate comparison breaks down exactly how to choose.
Want to dig deeper? See our guides to magnesium glycinate vs citrate, the best magnesium for sleep, and the best magnesium for leg cramps.
Bottom Line: Which Should You Buy?
For most people: NOW Magnesium Citrate 200mg. Trusted testing, flexible dosing, and a 250-count bottle that lasts.
On a budget: Nutricost Magnesium Citrate 420mg. Full-strength servings, third-party tested, lowest cost per milligram.
Premium pick: Pure Encapsulations Magnesium (Citrate). Practitioner-grade purity with no unnecessary excipients.
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Frequently Asked Questions
What is magnesium citrate good for?
Magnesium citrate is a well-absorbed form of magnesium used to correct low magnesium intake, support muscle and nerve function, and — at higher doses — relieve occasional constipation, since citrate draws water into the bowel. It's one of the most studied and widely available magnesium forms.
Is magnesium citrate better than magnesium glycinate?
They're both well absorbed. The practical difference is the gut effect: citrate has a mild osmotic laxative action that glycinate lacks. If you tend toward constipation, citrate is often the better fit; if you have a sensitive stomach or want magnesium mainly for sleep and relaxation, glycinate is usually gentler.
Will magnesium citrate make me run to the bathroom?
At typical supplement doses (200-400mg elemental magnesium per day, taken with food) most people tolerate citrate well. The strong laxative effect people associate with 'magnesium citrate' comes from high-dose liquid preparations used for bowel prep, which contain several times more than a supplement serving. Start with one serving and increase gradually.
When should I take magnesium citrate?
Any consistent time works. Many people take it with dinner or before bed, since magnesium supports muscle relaxation. Taking it with food improves comfort and absorption. If you take thyroid medication or certain antibiotics, separate magnesium by at least 2-4 hours.
How much magnesium citrate should I take daily?
The recommended dietary allowance for magnesium is 310-320mg per day for adult women and 400-420mg for adult men, from food and supplements combined. Most citrate supplements provide 150-420mg elemental magnesium per serving. The tolerable upper intake for supplemental magnesium is 350mg per day unless a doctor advises otherwise.
Sources & Research
This article was informed by peer-reviewed research and clinical guidelines. The Supplements Corner Editorial Team reviews published literature to ensure accuracy.
Dosage Reference
The RDA for magnesium is 310–320mg/day for adult women and 400–420mg/day for adult men (all sources combined). The NIH sets the tolerable upper intake for supplemental magnesium at 350mg/day for healthy adults. Take citrate with food; separate from thyroid medications and certain antibiotics by 2–4 hours.
Key Studies Referenced:
- Walker AF, et al. (2003). "Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study." Magnesium Research, 16(3), 183-191.
- Lindberg JS, et al. (1990). "Magnesium bioavailability from magnesium citrate and magnesium oxide." Journal of the American College of Nutrition, 9(1), 48-55.
- NIH Office of Dietary Supplements. "Magnesium: Fact Sheet for Health Professionals."
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting, stopping, or changing any supplement regimen. Individual results may vary.
