Life Extension Magnesium Caps 500mg
Best budget magnesium — delivers high potency from multiple forms at an unbeatable price. Solid choice for daily magnesium maintenance.
- 500mg from three forms (citrate, oxide, succinate) for broader coverage
- Very affordable
- Vegetarian capsules
- High potency per serving
- Contains magnesium oxide (lower absorption than glycinate)
- Large capsules
- 500mg may be too much in a single dose for some
Life Extension Magnesium Caps are our top budget pick for daily magnesium supplementation. At roughly $14 for 100 vegetarian capsules, you get 500mg of magnesium per serving from three complementary forms — making this one of the most cost-effective ways to address the magnesium gap that affects most adults over 50.
What Is It?
Life Extension Magnesium Caps is a high-potency magnesium supplement that combines three forms of magnesium — citrate, oxide, and succinate — to deliver 500mg of elemental magnesium per serving. Rather than relying on a single form, this blend aims to provide different absorption profiles and broader mineral coverage.
Life Extension has been formulating supplements since 1980 and is known for their research-driven approach. This product is manufactured in GMP-certified facilities and uses vegetarian capsules.
What’s Inside
Each serving (one capsule) provides:
- Magnesium citrate — one of the better-absorbed forms, commonly used for both heart health and general supplementation
- Magnesium oxide — high elemental magnesium content but lower absorption rate (~4-5%); contributes to the total potency
- Magnesium succinate — less common form that may support cellular energy production via the Krebs cycle
The total elemental magnesium per capsule is 500mg, which exceeds the RDA for both men (420mg) and women (320mg) over 50.
What the Research Says
Magnesium’s role in cardiovascular health is extensively documented. It helps regulate heart rhythm, supports healthy blood pressure, and is involved in over 300 enzymatic reactions in the body.
A 2016 meta-analysis of 34 randomized controlled trials published in Hypertension found that magnesium supplementation reduced systolic blood pressure by an average of 2 mmHg and diastolic by 1.8 mmHg. A 2013 study in The American Journal of Clinical Nutrition linked higher magnesium intake to a 22% lower risk of heart failure.
The specific concern with this product is the inclusion of magnesium oxide. While oxide has the highest elemental magnesium content by weight, its absorption rate is considerably lower than citrate or glycinate. However, a 2019 study in Nutrients showed that even magnesium oxide contributes meaningfully to magnesium status when taken consistently over time. The blend approach here means you’re getting both well-absorbed (citrate) and high-content (oxide) forms together.
Who Is This Best For?
Life Extension Magnesium Caps are ideal if you:
- Want a reliable daily magnesium supplement at a budget-friendly price
- Need high-potency magnesium (500mg) to address a known gap in your diet
- Prefer vegetarian capsules
- Are comfortable with a multi-form blend rather than a single specialized form
- Take medications that deplete magnesium (PPIs, diuretics, certain antibiotics)
This may not be the best choice if you have a sensitive stomach (start with a lower-absorption form like glycinate instead), need magnesium specifically for sleep (glycinate or threonate would be better), or prefer a smaller capsule size.
How to Take It
Life Extension recommends one capsule daily. For optimal results:
- Consider splitting the dose. If you can open the capsule or find a way to take half, absorbing 250mg twice daily is more efficient than 500mg at once. Your intestines have a finite capacity to absorb magnesium at any given time.
- Take with food to minimize any digestive effects and improve absorption of the citrate form.
- Space away from medications by at least 2 hours. Magnesium can interfere with absorption of antibiotics, bisphosphonates, and certain blood pressure medications.
If you experience loose stools, reduce the dose or split it across the day. The oxide component is more likely to cause this effect.
The Bottom Line
At $14 for a 100-day supply, Life Extension Magnesium Caps cost roughly $0.14 per day — making them one of the best values in the magnesium category. The three-form blend provides broad coverage, and the 500mg dose is sufficient to address the deficiency that affects the majority of adults over 50.
The inclusion of magnesium oxide is the main tradeoff. If maximum absorption is your priority, a pure glycinate product like Doctor’s Best would be a better choice. But for straightforward daily magnesium maintenance at a price that’s hard to beat, Life Extension delivers.
As with any supplement, consult your healthcare provider before starting magnesium, especially if you take heart medications, blood pressure drugs, or have kidney concerns.
Frequently Asked Questions
Is magnesium oxide in Life Extension Magnesium Caps a problem?
Magnesium oxide has lower bioavailability (around 4-5% absorption) compared to citrate (25-30%) or glycinate (higher still). However, Life Extension combines oxide with citrate and succinate, so you're getting a blend of absorption rates. The oxide portion also contributes to the high total magnesium content. For general daily maintenance, this blend works well. If you have a specific deficiency or need maximum absorption, a pure glycinate product may be more appropriate.
Can I take 500mg of magnesium in one dose?
Some people tolerate 500mg at once without issues, but splitting the dose may be better. Taking 250mg twice daily can improve absorption (your body absorbs magnesium more efficiently in smaller amounts) and reduce the chance of digestive discomfort. If you experience loose stools, try splitting across morning and evening.
Why do adults over 50 need more magnesium?
Several factors reduce magnesium status as you age: decreased intestinal absorption, increased urinary excretion, medications that deplete magnesium (proton pump inhibitors, diuretics, certain blood pressure drugs), and dietary changes. Studies estimate that 60-70% of adults over 60 don't meet the recommended daily intake of 320mg (women) or 420mg (men). Supplementation helps close this gap.
Is Life Extension a reputable brand?
Life Extension has been in the supplement industry since 1980 and is known for science-forward formulations. They invest in clinical research, publish their own peer-reviewed journal, and maintain rigorous quality control with third-party testing. Their products are manufactured in GMP-certified facilities. They are one of the more trusted brands in the longevity and health optimization space.