Supplements that have been shown to improve insulin sensitivity include:

1. Chromium, and I recommend 200 to 400 micrograms (mcg) of chromium three times per day in the polynicotinate or picolinate form, as one recent (non-HIV) study with type 2 diabetics showed that 1,000 mcg. of chromium per day increased insulin sensitivity by about 40 percent without toxicity.

2. The herb silymarin (milk thistle) as a "standardized extract" in a dose of 200 mg three times per day has been shown to be effective in improving liver function and improving insulin sensitivity. It is also great stuff for protecting your liver.

3. The best supplement for improving insulin sensitivity and glucose disposal may be the antioxidant called alpha lipoic acid (ALA), at 100 to 300 mg three times per day. ALA improves insulin dependent and non-insulin dependent glucose uptake, and it has been shown to effectively help lower blood sugar comparably to insulin itself.

4. Also worth considering is the dietary supplement called EPA (fish oil), which has been shown to reduce insulin resistance, and lower triglycerides somewhat in a study with HIV(+) men.

5. And taking a very high potency complete multivitamin, multimineral, antioxidant supplement that includes chromium, vitamins A, D, E, and calcium and magnesium will help improve insulin sensitivity.

6. High dose biotin supplementation is frequently prescribed by nutritionally-oriented medical doctors to improve glucose metabolism in diabetes. High dose biotin is also known to improve diabetic neuropathy. The dose of biotin that is commonly used is 1,000 mcg three times per day.

7. As noted by the late Canadian protein chemist Chester Myers, Ph.D., N-acetyl cysteine (NAC) can be a valuable addition to the supplements that address lipodystrophy, because of its effect on improving glutathione, which is necessary for glucose tolerance factor metabolism. I suggest 500 to 1,000 mg of NAC three times per day.

8. Also carnitine, as the prescription version called Carnitor, would be beneficial in higher doses, about 500 to 1,000 mg three times per day. Carnitine helps to lowers triglycerides, which are sometimes elevated when lipodystrophy is present. Note that the acetyl-L-carnitine form of carnitine may be more effective than plain L-carnitine, but it is more expensive

9. supplementing with high doses of the amino acid L-glutamine, helps reduce the catabolic process of breaking down muscle tissue. I recommend high doses on a calorie resticted diet (low cal, no effect on insulin levels, and anti catabolic if taken in split doses throughout the day). It is the most prominent amino acid in muscle. Glutamine has also been shown to have a powerful effect on improving glutathione production, and glutamine improves insulin sensitivity.

For in depth information about the mechanisms of insulin transport and perhaps the most potent insulin mimmicker availiable - metformin/glucophage; see the following thread:
Metformin/glucophage-all you need to know!