NOW Magnesium Bisglycinate Powder
Brand: NOW · Form: POWDER [E0162] On Market
Our assessment
The evidence shows that while calcium is essential for bone health, supplementation is not for everyone. For most adults, getting calcium from food is preferred, and taking a supplement like NOW Magnesium Bisglycinate Powder—which contains calcium—requires careful consideration of your total intake [NIH ODS].
How it works
Calcium acts as a mineral building block for your bones, supporting bone density and mineral deposition [NIH ODS]. It also plays a key role in neuromuscular relaxation, meaning it helps your muscles relax and your nerves signal properly [NIH ODS]. Think of it as the foundation that keeps your skeletal system strong and your muscle function smooth.
Safety profile
FDA received a total of 592,059 adverse event reports across all supplement categories, though specific data for this product is not available. For calcium specifically, high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Very high levels in the blood and urine can cause poor muscle tone, poor kidney function, low phosphate levels, constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS]. Calcium can also reduce absorption of medications like bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].
Our recommendation
Start by evaluating your dietary calcium intake before adding this supplement. Most adults need 1,000–1,200 mg daily from all sources, but more is not better [NIH ODS]. If you decide to use this powder, take it separately from any medications listed above by at least 2 hours. Data not available for specific dosing of this product due to label restrictions.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 8.0 oz. 227.0 g |
| Market Status | On Market |
How to Read This Label
Supplement labels contain several key sections regulated by the FDA:
- Serving Size — The recommended amount per dose. Always check this — some products require multiple capsules per serving.
- Amount Per Serving — Shows the quantity of each nutrient in the product, typically in IU (International Units), mg (milligrams), or mcg (micrograms).
- % Daily Value (%DV) — Indicates how much a nutrient in a serving contributes to a daily diet. 5% DV or less is low; 20% DV or more is high.
- Other Ingredients — Lists inactive ingredients like fillers, binders, and capsule materials (e.g., gelatin, cellulose, magnesium stearate).
- Suggested Use — The manufacturer's recommended directions for taking the supplement, including timing and dosage.
Source: FDA Dietary Supplement Labeling Guide