Yes. It does run smaller. Unless you like a very tight fit (some do), then I would order a large.
thanks for your answer
This shirt does run smaller than most brands. I normally wear XL, but XXL fits me better in this particular shirt. I've learned that with Icebreaker tops, it's important to rest your cursor on the size icons to see the pop-ups that show actual chest sizes in inches. In this case, I see that Medium is 36-38.75, and Large is 41-42. I have found these chest sizes to be more reliable than Icebreaker's XL and XXL designations. if you're in-between, you may want to go with the large, and shrink it down with a couple of lukewarm washes if it's too big.
Good luck I hope this helps.
yes - runs a size small. I normally wear an XL and ordered a 2XL and it fits perfect. That is unless you want a tight fit.