Skinceuticals Tripeptide Neck Repair

Wanted to LOVE the Skinceuticals Tripeptide Neck Repair. I began using every few days (as I remembered) but made a priority to use it nightly for the last 3 weeks. I kept itching my neck during the day but chalked it up to my dry skin and the fall. I use Skinceuticals vitamin C serum and Garnier hydra melon SPF 30 without issues. I do think my neck (aside from the dark blotches) lines look finer. I have mildly sensitive skin but have used Rx retinols before without an issues so maybe the peptides?

On the skin store there are similar reviews regarding neck rashes. I guess it wasn't meant to be.