I'm not sure what you mean by your question? If you're asking 'why it has a shorter half-life, you'd have to read up on some scientific journals. If you're asking me to confirm whether it has a shorter half life than DMSA, then the answer is yes.

Drop Cutler an e-mail if you're unsure, but I have his book - and he states that once you move onto ALA - it should be every 3 hours. I take my DMSA every 3 hours alongside it (as does everyone else), because it's easier to manage.