Take something with a pinch of salt
Definition 1 of 1
Pro Tip 1/3Credibility Issue
Use the phrase when you doubt the truthfulness or accuracy of what someone says. 
The politician made some bold claims, but I took them with a pinch of salt.
Pro Tip 2/3Not Literal
Remember, 'with a pinch of salt' is an idiom; it's not about actual salt. 
If he says he's an expert, take it with a pinch of salt.
Pro Tip 3/3Subtle Skepticism
The phrase expresses a light, not aggressive, skepticism towards information. 
She claims to have seen a celebrity, so I'm taking that with a pinch of salt.