NOW Molecularly Distilled Omega-3

Our assessment

The evidence shows that NOW Molecularly Distilled Omega-3 is a product you should evaluate carefully, especially regarding its calcium content. While the label lists ingredients, the NIH data on calcium reveals important considerations for your health. You need to be aware that high calcium intakes might increase the risk of heart disease and prostate cancer, and that taking calcium supplements can reduce the absorption of several medications including bisphosphonates, tetracycline antibiotics, fluoroquinolone antibiotics, levothyroxine, and phenytoin [NIH ODS].

How it works

Think of calcium as a structural builder for your bones. It supports bone density and mineral deposition through bone mineralization, and it also helps your muscles relax and your nerves signal properly through neuromuscular relaxation [NIH ODS]. However, because this Omega-3 product may contain calcium, you should consider how it fits into your total daily intake from all sources, including food and other supplements.

Safety profile

FDA received 592,059 total adverse event reports across all products. For calcium specifically, high levels in your blood and urine 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] [FDA data]. You should be especially cautious if you take any of the medications listed in the interactions section, as calcium can reduce their absorption [NIH ODS].

Our recommendation

Start by checking your total daily calcium intake from all sources before adding this product. If you take any prescription medications, separate your calcium supplement from those doses by at least 2 hours to avoid absorption issues. Monitor for the side effects listed above, particularly nausea, constipation, or changes in urination. Data not available on the specific omega-3 dosage per serving, so you should consult your healthcare provider to determine if this product is appropriate for your individual needs [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