My doctor recently prescribed Lovaza and Niaspan to help lower my triglycerides and cholesterol. Can't I just take an OTC omega-3 and timed-release niacin with the same benefits?
You probably can, but.....
Lovaza and Niaspan are regulated by the FDA. Supplements, which include omega-3 and niacin, are not; by going with the prescription medication, you know exactly what you are getting.
If you choose to go the supplement route, discuss it with your physician. You may need to change to the prescription form if your cholesterol numbers do not improve.
To your health,
This is why so many people fail the supplement route unfortunately, there aren't great sources of information about what to take and what not to take, etc. With respect to niacin, it has to be nicotinic acid to lower cholesterol, not niacinamide, and not "no-flush" inositol hexanicotinate. The alternatives to Niaspan (extended release nicotinic acid) that have been objectively shown to be safe and effective are Slo-Niacin and Enduracin, according to several published lipid experts. Regardless of which form of niacin you take, you need physician supervision and periodic monitoring of liver function.
I'm not as familiar with the Omega 3 options, but in order to lower Trigs with fish oil, you generally need to take a lot of capsules, which then comes with a calorie load, and a potential increase in LDL.