Thymalin is not a single compound but a mixture — a polypeptide complex extracted from calf thymus, made up of many peptides of different sizes. That makes it one of the more unusual items in the catalog.
Vestrand supplies it as one production lot at a time, prepared for third-party analysis; for a multi-component material the lot certificate is where the characterisation lives, and it publishes to the verification page.
Because it is a mixture rather than a single molecule, several structural details other products list simply do not apply here — there is no single value to state for a material like this. A naming trap is also worth flagging: a search on the name can redirect to an unrelated defined compound whose figures we do not borrow.
For laboratory research use only. Not for human or veterinary use.