A review summarizes similar effects across mice and cashmere goats (Dai et al., 2021, DOI), and one study tested thymic peptides on cultured human hair follicles (Meier et al., 2012, DOI)
If you bought it from a UK supplier then it's much more likely that your they have had them stored at room temperature for days/weeks/months
Clinical data confirms low side effects with proper use
first reported a polymorphism in GPx1, namely, a substitution at codon 198 of either proline (Pro) or leucine (Leu), Pro198Leu (SNP: 1050450), in lung cancer [87]
For people with serious deficiencies or absorption issues, this difference can be life-changing
The approach works, but the effects are temporary and require repeated treatments