DHA-500 Double Strength 1 g (1000 mg) by Now Foods

This is a DHA-weighted fish oil for adults who eat little oily fish and want more DHA per softgel than a standard fish oil gives. It is a reasonable pick if your Omega-3 Index has come back low, or if salmon, sardines and mackerel rarely make it onto your plate. If your main concern is high Triglycerides, that calls for larger combined amounts of EPA and DHA under a clinician's direction, and a prescription omega-3 may be the better tool.

Each softgel holds 1 g (1,000 mg) of fish oil concentrate from anchovies, sardines and tuna, in which DHA is the larger share. DHA is the main omega-3 in the brain and the retina, where it is built into cell membranes; EPA is the partner omega-3 more involved in inflammatory signaling and triglyceride metabolism. The label describes the oil as molecularly distilled and tested for contaminants such as PCBs, dioxins, mercury and other heavy metals, and the softgel is enteric coated so it passes through the stomach before dissolving.

One softgel provides 500 mg of DHA and 250 mg of EPA. The label directs 1 softgel 1 to 2 times daily with food; fat in the meal improves omega-3 absorption. Swallow it whole: chewing or cutting defeats the enteric coating. One softgel a day is a reasonable place to start, and the second is worth discussing with your clinician if your Omega-3 Index stays low. Store the bottle in a cool, dry place after opening.

Fish oil has a mild effect on platelets. At the labeled 1–2 softgels a day the added bleeding risk is small, but if you take warfarin or another anticoagulant or an antiplatelet medicine, or have a bleeding disorder, clear it with your prescriber, and tell your surgical team before a planned operation. High intakes of omega-3s have been linked in trials to a small increase in atrial fibrillation, so ask your cardiologist first if you have a heart rhythm condition. It contains fish and bovine gelatin. The label is for adults only and says to consult a physician if you are pregnant or nursing, take medication or have a medical condition.

Omega-3s work by gradually changing the makeup of cell membranes, so nothing happens overnight. The Omega-3 Index typically takes 3–4 months of steady intake to settle at a new level; retest then. Trials of DHA for memory or focus in healthy, well-nourished adults are mixed, so do not expect a noticeable effect there. Standard fish oils carry more EPA than DHA, and algae-based DHA is the alternative if you avoid fish or gelatin.