NOW L-Arginine Amino Acid 500 mg
Brand: NOW · Form: CAPSULE [E0159]
Our assessment
The evidence shows that the supplement you are asking about is NOW L-Arginine Amino Acid 500 mg. However, the data provided is for the ingredient Calcium, not L-Arginine. Because of this, our assessment is limited. We cannot confirm any benefits or mechanisms for L-Arginine based on the supplied data. For Calcium, the data shows it supports bone mineralization and neuromuscular relaxation [NIH ODS].
How it works
Based on the data for Calcium, it acts as a master regulator for bone density and mineral deposition, and it supports muscle relaxation and nerve signaling [NIH ODS]. No data was provided on how L-Arginine works.
Safety profile
FDA received 592,059 total adverse event reports across all supplements, but no specific report count is available for this product [FDA data]. For the ingredient Calcium, side effects from high intake include constipation, nausea, weight loss, extreme tiredness, frequent need to urinate, and abnormal heart rhythms [NIH ODS]. Data not available for L-Arginine side effects.
Our recommendation
We cannot make a recommendation for NOW L-Arginine Amino Acid 500 mg because the data provided does not contain any information on L-Arginine. For the ingredient Calcium, if you choose to take it, be aware it can reduce absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS]. You should consult your doctor or pharmacist before starting any new supplement.
AI-assisted analysis. Data sourced from NIH DSLD.
Supplement Facts
| Brand | NOW |
|---|---|
| Serving Size | |
| Contents | 250.0 Capsule(s) |
| Market Status | Off 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