NOW Sports Branched-Chain Amino Acid Powder

Our assessment

The evidence shows that this product contains calcium, not branched-chain amino acids. For general health, calcium is essential, but the specific benefits you might expect from a BCAAs supplement are not supported by the data provided. The RDA for calcium is 1,000 mg for most adults, but you should note that the product label does not specify the exact amount per serving [NIH ODS].

How it works

Think of calcium as a structural and signaling powerhouse. It supports bone mineralization by helping deposit minerals into your skeleton, and it plays a key role in neuromuscular relaxation, allowing your muscles to relax and your nerves to fire properly [NIH ODS]. These mechanisms are critical for daily movement and bone strength.

Safety profile

FDA has received a total of 592,059 adverse event reports across all dietary supplements, though specific reports for this product are not available. For calcium, some research suggests that high intakes might increase the risk of heart disease and prostate cancer [NIH ODS]. Side effects from excessive calcium include 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]. Additionally, calcium can reduce the absorption of several medications, including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

Our recommendation

If you are looking for a branched-chain amino acid supplement, this product is not what it appears to be based on its ingredients. If you are seeking a calcium supplement, look for a product with a clear dose on the label and take it with food. Be aware of the potential medication interactions listed above, and do not exceed 2,500 mg of total calcium daily from all sources without medical supervision [NIH ODS]. Data not available on the exact calcium dose per serving from the label provided.

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