Airport security, police, and TSA have seen this for years and are well aware that many travelers are supplement crazy these days. I travel with ziplock bags full of supplements, including white Vanilla protein powder in a baggie. I joked about it one time with TSA showing an agent the baggie of white Protein Powder, and he said something like, "Yea, we see a lot of protein powder and other supplements every day."
I've never had an issue. GNC stores are as popular now as McDonalds. It's common.
Enjoy.