Do gifts to other players come from my inventory in Avengers Alliance?

When I "gift" items to my allies in Avengers Alliance, do they come from my inventory? It's logical that they would, of course, but I don't notice my amount of SHIELD points going down when I send them to other people. Maybe they don't get deducted until the other player logs into Facebook and picks up the gift, but I know I've accidentally "overdrawn" my account without any consequences.

I don't have an authoritative source for this, but based on my experience it seems like the gift system is separate from personal points as I've been able to gift and "return the favor" many times over when my balance is zero. (Not to mention the "Norton Shield" item, which is only available if someone gifts it to you.)