The pictures, in which the 24-year-old actresses appear dressed in skimpy outfits, was criticized Wednesday by the Parents Television Council, which said the pictorial "borders on pedophilia."
Agron weighed in on her blog Wednesday night, apologizing to anyone who might be "hurt" or "uncomfortable" by the photos but noted that "we are not the first" public figures to push the envelope.
"Nobody is perfect, and these photos do not represent who I am," she wrote, adding that GQ "asked us to play very heightened versions of our school characters. A 'Hit Me Baby One More Time' version. At the time, it wasn't my favorite idea, but I did not walk away."
The actress -- who wrote she was speaking on behalf of herself only and not her co-stars, the show or Fox -- also argued that parents have ways of keeping this kind of content away from their kids.
"And if your eight-year-old has a copy of our GQ cover in hand, again I am sorry," she wrote. "But I would have to ask, how on earth did it get there?"