I would call IGF a grey area in the law. If you are buying it to use on your test rats than it is legal. The problem is that it is a drug, however it is not a scheduled drug by the FDA, it is a research drug so that is where the grey area exists. If you are that worried about it you might seek to ask a attorney that is fimiliar with steriods.
in the United States, IGF-1lr3 is a research compound. It is legal to own this substance to the best of my knowledge (at current time). I am not an attorney, so please review your local law(s) regarding possession and administration of this therapeutic protein.