Peptides? I wouldn’t even bother. Barely use em as it is. I always travel with gear, but only what I know I will need. 1 vial max. Throw it in with all my toiletries in my little toiletry bag. Syringes can usually be bought at my destination.
You have to understand that customs and security for nearly every country are looking for the big fish. The traffickers. The smugglers.
Its always a gamble and a risk. If you’re worries enough to ask the internet, avoid the anxiety and leave em at home.