Katherine Heigl and her new shade of washed-out blonde were on Letterman last night. In this latest appearance, she wasn’t complaining bitterly about her work schedule or trying to seem human by explaining how heartbreaking motherhood can be. She was puffing on an electronic cigarette and trying to act badass. Heigl explained that she’s trying to quit smoking after multiple attempts. The electronic cigarette contains liquid nicotine and emits a water vapor that’s harmless and gives the user the feeling of smoking. Betty Confidential has more on Heigl’s Letterman appearance and some background on the device she was using:

It was a TV scene straight out of the 1960s, when everybody smoked everywhere: Katherine Heigl fired up a cigarette while talking with David Letterman. With the widely known health risks of cigarettes, they’ve been banned everywhere from offices to restaurants.

But Heigl smoked an e-cigarette, an electronic device that provides short hits of nicotine or a vapor that actually tastes like nicotine. The smoker blows the smoke out, just like they would do with a “real” cigarette. Heigl, 31, began smoking at age 25 (most users start much earlier) and told Letterman that she really wants to quit but hasn’t been able to. “I did the patch, I did the gum, I did the [prescription medicine] Chantix twice. I went bananas,” the actress told Letterman, according to tvsquad. But the e-cigarette seems to be working.

Heigl even convinced Letterman, a cigar smoker, to try the e-cigarette. He said it made him feel dizzy; people often have that side effect when taking nicotine for the first time, or after a long period of not using it.

The drawback to the e-cigarette : It’s addictive, just as nicotine gum is. “I’m totally addicted to the device,” Heigl said to Letterman.

So what’s the difference from being addicted to tobacco as we know it? It depends on how much nicotine you’re using in in the electronic cigarette. The amounts are designated low to extra-high. Heigl didn’t say what the level of nicotine was in her smokes.

The federal Food and Drug Administration hasn’t ruled yet on the e-cigarettes, although preliminary tests have shown that there are often low levels of nicotine even in cigarettes that say they are nicotine-free. The FDA also has said that the products should be sold with health warnings and that they’re concerned that the e-cigarette is being marketed to young people.

E-cigarettes have already been banned in Australia and Canada, and while it’s not certain whether that will happen in the U.S., Heigl might want to stock up on her supply.

[From Betty Confidential]

Heigl is promoting yet another romcom that looks like a piece of crap (and contains multiple crap jokes), Life As We Know It, which is out October 8 and co-stars Josh Duhamel. Her only other film this year, Killers, bombed at the box office and was critically panned. I’m obviously not a fan of hers, but good for her for quitting smoking. She may want to quit smoking the electronic cigarettes too, though. An FDA study in 2009 found that many contained dangerous carcinogens including chemicals found in antifreeze. At least the smoker is the only one being exposed, but it sounds scary and people should be warned. Up until earlier this month, the FDA had not regulated e-Cigarettes, although they won a court battle this year and recently announced that they planned to do so.

Let’s get back to Heigl’s hair – as Kaiser mentioned it’s a very bad shade for her. Here’s a comparison photo from back when she had dark Dallas-style hair. It was just as bad and it’s hard to tell which is worse. She’s so pretty and her hair just ruins it for her.

Blonde photos are from 9/27/10. Credit: Fame