Prime Nutrition Precision Series L-Leucine Amino Support

Our assessment

The evidence shows that the Prime Nutrition Precision Series L-Leucine Amino Support product’s primary ingredient is L-Leucine, but the data provided does not include any specific information on L-Leucine. Data not available for L-Leucine. The ingredient data we do have is for calcium, which is also listed on the label. Our assessment is that without specific data on L-Leucine, we cannot evaluate its effectiveness or risks for you.

How it works

Based on the data provided for calcium, which is an ingredient in this product, it supports bone mineralization by helping deposit minerals into your bones and supports neuromuscular relaxation for proper muscle and nerve function [NIH ODS]. No mechanism data is available for L-Leucine itself.

Safety profile

For the calcium component, high intakes might increase the risk of heart disease and prostate cancer. High blood and urine levels 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]. The FDA has received a total of 592059 adverse event reports across all supplement categories, though specific reports for this product are not available [FDA data].

Our recommendation

We cannot make a confident recommendation for this product because the primary ingredient, L-Leucine, has no data provided for analysis. For the calcium content, you should be aware that calcium can reduce absorption of medications like bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS]. Consult your healthcare provider before use, as no specific safety or efficacy data for this supplement is available.

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