I checked some back postings of a list I am on for natural alternatives for emotional problems, and these are two postings that are related to your question:
"Secondly, I believe tryptophan to be far superior to 5-HTP. There is much
written on 5-HTP not being able to pass
the BBB efficiently and in my personal experience with myself and patients, I see tryptophan working much better.
(and yes you can still purchase it, always could). Tryptophan is best when
taken with carbohydrates, I would suggest
in the first trimester to obtain it mostly from food sources since it's easy to
do so - a handful of cashews contains 410 mg."
"The symptoms you mention appear to be linked to serotonin
deficiency. 5-HTP is a great precursor for serotonin production. We
use a formulation that includes a therapeutic supply of 5-HTP for
both of our Migraine Prevention and Depression Management
protocols. The product name is Serotona and has been used during
pregnancy and breastfeeding with the OK of obstetricians."
Hope this helps.