GNC Pro Performance Amino

Our assessment

The evidence shows that the primary active ingredient in GNC Pro Performance Amino is calcium, based on the data provided. For general health, calcium is essential, but the specific benefits of this product for amino acid support are not detailed in the available data. Our assessment is that you should understand the role of calcium in your body before considering this supplement, as its primary function is not typically for amino acid support [NIH ODS].

How it works

Think of calcium as a master regulator for your bones and muscles. It supports bone mineralization, helping to build and maintain bone density. It also plays a key role in neuromuscular relaxation, which means it helps your muscles relax and your nerves send signals properly after you exercise [NIH ODS].

Safety profile

FDA received a total of 592,059 adverse event reports across all supplements, but the specific count for this product is not available. For calcium specifically, high intakes might increase the risk of heart disease and prostate cancer. Very high levels in the blood can cause poor muscle tone, poor kidney function, constipation, nausea, weight loss, extreme tiredness, frequent urination, and abnormal heart rhythms [NIH ODS] [FDA data]. Calcium can also reduce the absorption of medications like bisphosphonates, tetracycline antibiotics, and levothyroxine [NIH ODS].

Our recommendation

We recommend you check your current calcium intake from food and other supplements before adding this product. If you are taking any medications, especially antibiotics or thyroid medication, speak with your doctor about potential interactions. Without specific data on the amino acid content of this product, we cannot recommend it for muscle building or recovery over other well-studied sources of protein or amino acids [NIH ODS].

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