The basic dose we advocate for the Track Your Plaque program is 1200 mg per day of EPA + DHA, the essential omega-3 fatty acids.
1200 mg EPA+DHA is generally obtainable by taking 4 capsules of 1000 mg of fish oil, since the majority of preparations contain 180 mg EPA and 120 mg DHA per capsule.
But how will you know if a higher dose wouldn't be even better?
The principal parameter to look at is triglycerides. If triglycerides remain above 60 mg/dl, we usually consider increasing fish oil.
Another measure that's very important is intermediate-density lipoprotein, or IDL, also called "remnant lipoproteins" on a VAP panel. Persistence of any IDL or remnant lipoproteins is reason to consider more fish oil. Most commonly, if there is some persistence of either, we increase fish oil to 6000 mg per day of a standard preparation, or 1800 mg/day of EPA+DHA.
The only time we see persistence of IDL or remnant lipoproteins with this higher dose is when triglycerides are really high. If starting triglycerides are, for instance, 500 mg/dl, then even this higher dose may be insufficient. This is when more highly concentrated preparations of fish oil may be necessary, occasionally even the prescription form, Omacor. (We currently use Omacor only when high doses of EPA+DHA are required, most because of its outrageous cost. Two capsules per day costs around $120 per month; three capsules per day to provide 1800 mg/day of EPA+DHA costs $180 per month. I think this is outrageous and so we use it only when absolutely necessary.)
You might even argue that a higher dose of 1800 mg EPA+DHA, or 6000 mg of a standard capsule, might be preferable for more assured reduction of heart attack risk--even when triglycerides and IDL are perfectly under control. I wouldn't argue with you. But you won't observe any measurable feedback that tells you that a heightened effect is being obtained. I take that dose myself, in fact, despite the fact that elimination of wheat products and weight loss was sufficient to drop my triglycerides to the target level. I figure it's a small additional effort for added peace of mind.