By BUCK WOLF

Aug. 9, 2005 — When baseball star Rafael Palmeiro started advocating America's most celebrated performance enhancing drug — Viagra — the slugger-turned-pitchman got kudos for admitting he needed some off-the-field help.

Sure, celebrities don't necessarily use products they endorse. After leading the New York Jets to the 1969 Super Bowl, Joe Namath shocked TV audiences by squeezing into Beauty Mist pantyhose. But no one ever thought Namath wore ladies' underwear.

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Palmeiro, however, left little doubt. A full-page ad in "The New York Times" launching the ad campaign highlighted his achievements — more than 450 home runs and three gold glove awards — with the slugger boasting, "I take batting practice, I take infield practice … I take Viagra."

In all his time pitching the little blue potency pill, the 40-year-old first baseman never said why he was getting treatment for erectile dysfunction. As we all know, Viagra is not supposed to be used recreationally. "Let's just say it works for me," he claimed in commercials, and he didn't care to elaborate.

Of course, Palmeiro's credibility has since come under question. In March, he testified before Congress and solemnly said, "I have never used steroids. Period." Then, shortly after hitting his 500th home run, and his 3,000th hit — two achievements that would otherwise guarantee membership in Baseball's Hall of Fame — major league officials announced that he tested positive for steroids and would be suspended.

Palmeiro now says he has never "intentionally used steroids," that he testified honestly before Congress, and will be vindicated when his case is further investigated.

It's still unclear what cloud will hang over Palmeiro's career, but it's fairly safe to assume that Pfizer would have preferred to have sent a scandal-free player up to bat as its spokesman. As Palmeiro's Viagra ads have been off the air for more than a year and a half, the company has been mum.

Nevertheless, the controversy just highlights risks companies take when picking spokesmen. Even the squeakiest of the clean is just a DUI away from falling from grace. Certainly, Kobe Bryant is not quite the same man we saw hawking McDonald's cheeseburgers in "We Love to See You Smile" commercials just a few years ago.

There was even a time in the early 1980s when companies were tripping over themselves to be associated with ear-chomping Mike Tyson. He got $1.25 million to appear in a Diet Pepsi commercial, and also appeared in ads for Toyota, Nintendo and Kodak.

More recently, Whoopi Goldberg's off-color jokes about President Bush during a John Kerry benefit last fall cost her a big fat endorsement deal with Slim-Fast. But once the damage is done, it's a public relations nightmare.

"It's a risk you take when you deal with personalities. That's why there are morals clauses in many endorsement contracts," says Mark Roesler, CEO of chairman CMG Worldwide, an entertainment marketing firm that represents more than 65 Hall of Fame baseball players. "But the power of using a celebrity to brand a product is so powerful, it makes the risk worthwhile."

While Roesler's undoubtedly right, here's a look at a few product endorsements with messages that have been forever mutated, thanks to a little celebrity scandal.

1. Giambi Swings Big for Body Odor
After reportedly admitting to a grand jury last year that he used steroids, Yankee star Jason Giambi is trying to resurrect his baseball career. In July, he was named the American League's Player of the Month.

At the start of the season, Giambi tearfully apologized to fans and clearly has some regrets. So must Arm & Hammer, the company that featured the hulking, six-foot-three first baseman in ads for Ultramax deodorant. The TV commercials highlighted his bulging biceps along with the slogan, "All the muscle a man needs."

2. Olsen Twins Don't Let Controversy Ruin a Happy Meal
Late last summer, several weeks after Mary-Kate Olsen was treated for an eating disorder, McDonald's France began featuring the Olsen twins on Happy Meals. The deal was apparently in place long before Mary-Kate checked into a Utah rehab center, and European TV spots went ahead as planned.

While a bone-thin Mary-Kate might not be the best inspiration to get kids to eat cheeseburgers, aren't the Happy Meal prizes the real reason why kids clamor for a trip to the golden arches?

In this respect, the Olsen girls did not disappoint. Kids could feast on offers for an official Mary-Kate and Ashley photo album or handbag. This was one McDonald's meal that couldn't be super-sized.

3. Beckham Dials Wrong Number
David Beckham has been expounding the virtues of Vodafone Live! cell phones for several years. But after a few tabloid dustups with women claiming to be mistresses, Beckham might not be so high on the marvels of modern telecommunications.

Both women supported their claims of an affair by handing over X-rated text messages supposedly sent by Europe's most famous athlete via his cell phone. Beckham's reign as the global face of Vodafone ends this year, and while both parties say this move comes by mutual consent, the controversial text messages couldn't have helped matters.

Perhaps Beckham could have avoided this controversy if he'd paid more attention to a Vodaphone commercial from 2002, in which the company played up text messaging as the newest form of digital foreplay. This non-Beckham ad featured the slogan, "Get your flirting over first.''

4. Kobe Spreads Himself Too Thin for Nutella
When Kobe Bryant faced sexual assault charges, he lost millions in endorsements, but the incident proved especially embarrassing for Nutella, the maker of a chocolate-hazelnut topping.

The company's slogan — "Kobe's Bryant's favorite spread" — didn't sound quite right given the basketball star's sexual misbehavior. In fact, it became an easy punch line for late night comics.

In July 2003, days after the story broke, The Italian confectioner pulled Bryant's image off promotional material and also stopped selling a Kobe bobble head doll.

Criminal charges against Bryant were dropped, and following a civil settlement, he issued a public apology to his accuser, a 19-year-old woman he says he thought had come to his hotel room for consensual sex.

Nevertheless, it seemed like the NBA had lost its most marketable player. He suddenly seemed the wrong man for Sprite to feature in an ad that urged TV viewers to "Obey Your Thirst, Trust Your Instincts."

Nevertheless, despite a dismal season, the Los Angeles Lakers star had a major breakthrough last month, when Nike featured him in a two-page spread in "Sports Illustrated." The return of Bryant features him staring at a long list of insults that have been leveled at him over the past two years: "Selfish … Uncoachable … Prima Donna … Not a leader … Not a Team Player."

"I think some people were surprised at the speed of Kobe's comeback. But, the way the way the situation was resolved, I don't think anyone doubted that he'd resume being a marketable personality," says Doug Drotman, head of the New York-based sports public relations firm Drotman Communications.

"What you will see is that Kobe will be marketed a little differently. That's inevitable. Because a change in public perception is something that can't be denied or avoided."

5. O.J. Simpson Puts Fork in Knife Deal
Damage control to save O.J. Simpson's mass marketing career began in 1994, almost as soon as he was charged with murdering his ex-wife and her friend Ron Goldman.

Ironically, three days before the butchered bodies were found, Simpson had been elected to the board of directors of a Connecticut company that imports and distributes Swiss Army Knives.

For the privilege of having a celebrity at company events, The Forschner Group was paying Simpson $10,000 a year, plus $1,000 for each meeting he attended. From his cell at the Los Angeles County Jail, Simpson sent a letter resigning from the board, figuring it best not to be associated with a knife company at a time when he was accused of hacking two people to death.

Buck Wolf is entertainment producer at ABCNEWS.com. "The Wolf Files" is published Tuesdays.