Weight-lifting magazines bulk up on ads for supplements. Beauty magazines keep up their looks with messages from makeup manufacturers. Cooking magazines gorge on ads for the choicest ingredients. Whatever their subject matter, special-interest magazines are often financially dependent on advertisers from the very industries they aim to cover.

It's no secret that this chumminess can affect a magazine's editorial content. Questionable claims about the best brand of eye shadow or olive oil may not be such a big deal, but what happens when a magazine focuses on much more complicated, life-and-death issues? Take the case of a publication targeted toward people with AIDS-and full of pharmaceutical ads for AIDS-fighting drugs. How well are readers served when advertisers have a vested interest in seeing the illness treated in a specific way?

The question is not an idle one: The number of large-circulation, disease-specific magazines is on the rise. The trend began less than a decade ago with POZ, A&U, and later HIV Plus-national magazines that set out to serve the HIV-AIDS community by profiling activists, sharing personal stories, and providing news on the latest medical treatments. Several cancer-specific titles can now be found on the news- stand as well.

The earliest ventures were not designed to rely solely on drug ads. Publishers first tried promoting the affluent 'gay demographic,' hoping to secure long-term contracts with high-profile general-interest advertisers; but mainstream clients quickly faded away when the audience proved more diverse-and less prosperous-than predicted.

The magazines survived in part by featuring more direct-to-consumer (DTC) ads placed by drug companies, promotions touting the health benefits of certain drug therapies. You've seen them: high-gloss shots of active, beaming patients followed by a page of government-mandated microscopic 'mouse print' that details, among other things, the drug's potentially nasty side effects. At first, the models featured in the ads were more somber and thoughtful, but as public understanding of HIV and AIDS has increased, so has the vitality of the people the ads depict.

Today, the vast majority of the ads in leading HIV-AIDS publications come from pharmaceutical manufacturers. From a financial standpoint, the switchover has been positive-one-to- three-page ads now plump up the magazines-but many readers wonder if these publications can continue to provide unbiased health information.

'I view POZ as a commercial venture,' says Bob Tracy, director of community affairs and education for the Minnesota AIDS Project. 'It's more about entertaining than informing me. If I'm looking for news, I'll go to one of the few publications that don't take advertising. I'm not saying I'll never look at POZ, because I do on a regular basis, but I do so with an understanding of the way publishing works. Sure, most of the advertising has no effect on content, but it may have an effect on 5 percent-and I don't know which 5 percent. It might be information that could affect my health.'