This is an excellent product that never causes "fish burps", at least in my experience.I’ve been taking a 1-gram "gem" per day for over a year and mysteriously — they’ve helped with occasional joint pains that I’ve developed with increasing age (I’m 62). Other fish-oil supplements I’ve taken over the past decade haven’t resulted in a similar benefit.I suspect this has to do with the large quantity of DHA this product contains. Plus, these "gems" have in reconstituted triglyceride (rTG) form; this structure is reported to be more readily absorbed than ethyl-ester (EE) forms of concentrated omega-3 fatty acids, which are more commonly found in high-end supplements & pharmaceutical drugs.Note the DHA hydrocarbon chain is very long, with 22 carbons. DHA isn’t abundant in most fish-oil supplements, while this Carlson product has a very high concentration compared to total omega-3s (78%). This compares favorably to the percent of DHA to total omega-3s in raw bluefin tuna (69%); light canned tuna in water (79%); and raw swordfish (64%) — these fractions were calculated from data available on the Carlson label and the website, nutritiondata.com.While the human body can synthesize DHA by adding carbons to the common form of omega-3 that’s in one’s diet (i.e., alpha-linolenic acid with 18 carbons, ALA) — the natural synthesis involves a difficult enzymatic process that’s not necessary with DHA that’s already in the food one consumes. Note DHA is a very important component of one’s nerve tissues, with the NIH’s website stating, "DHA makes up over 90% of the n-3 PUFAs in the brain and 10%–20% of its total lipids" ["n-3 PUFAs" = omega-3 polyunsaturated fatty acids].Anyway, I’m not aware of any scientific report that definitively shows that DHA helps with joint pain — all I know is that it manifests a positive benefit for me.