The 66-year-old, who continues to remain tight-lipped about a possible presidential run, was speaking during a Q&A with Twitter on Monday.
Tweeters used the #AskHillary hashtag on the social media site to have the former First Lady answer their questions.
Clinton responded by saying women should "grow skin as thick as the hide of a rhinoceros".
"I have certainly, as you can tell, have had to learn how to do that," she said. "There's a lot of good moisturisers I can tell you about if you're interested."
Clinton also visited the headquarters of Google and Facebook during her visit to Silicon Valley.