Dr. Clark Research Association Dr. Clark Zentrum Essential Amino Acids 500 mg

Our assessment

The evidence shows that this product is a calcium supplement, not a source of amino acids as the name suggests. It is critical you understand this distinction. The data confirms that calcium supports bone density and nerve signaling, but the specific formulation here lacks the clinical backing needed for a strong recommendation [NIH ODS].

How it works

Think of calcium as a structural foundation — it helps your body maintain strong bones through mineralization and supports proper muscle relaxation and nerve signaling [NIH ODS]. However, since this product is marketed as "Essential Amino Acids" but contains only calcium, you are not getting the protein-building blocks you might expect.

Safety profile

FDA has received a total of 592,059 adverse event reports across all supplement categories. For calcium specifically, high intakes might increase the risk of heart disease and prostate cancer. High levels in the blood or urine can cause poor muscle tone, poor kidney function, constipation, nausea, weight loss, extreme tiredness, frequent urination, abnormal heart rhythms, and a high risk of death from heart disease [NIH ODS] [FDA data].

Our recommendation

Data not available on the specific dose or purity of this brand. Because the product name is misleading — it contains calcium, not amino acids — we cannot recommend it for your intended use. If you need calcium, choose a product clearly labeled as such and talk to your doctor about the right dose for you, especially given the potential for medication interactions with bisphosphonates, antibiotics, and thyroid medication [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