Are supplements which claim increased absorption or improved bioavailability telling the truth? Is it worth paying more for these? Are there concerns?

Answer:

It is true that some supplements contain special ingredients, or enhancers,  which can improve the absorption or bioavailability (amount of ingredient circulating in your blood) of certain supplements, such as CoQ10, curcumin, milk thistle, green tea, grape seed, ginkgo,  and resveratrol. Enhancers typically act in the gut to either improve solubility or reduce the amount of enzymatic breakdown which occurs there. By allowing you to absorb more active ingredient, the supplement may be more potent, meaning that a smaller dose may be used. At the same time, enhancers may increase the absorption or otherwise interact with other supplements or drugs which you take, so it is important to use caution.

The four main types of enhancers currently found in supplements are emulsifying agents, like lecithin; self-emulsifying systems, which involve an oil; phytosomes made from phosphatidylcholine; and enzyme inhibitors, like black pepper extract. Liposomes and nanoparticles have also shown promise for improving absorption. Pros and cons of these enhancers, and the types of ingredients with which they may be useful, are discussed below (and in many of ConsumerLab.com's Product Reviews).  See the full answer >> >>