What is the difference between a formulation chemist and a co-packer?

A formulation chemist designs and stabilizes the chemistry — nutrient ratios, chelation, pH, and tank-mix compatibility — and delivers a batch record and SDS. A co-packer manufactures and fills at scale using that formula. Some contract manufacturers offer both. In the AJ Cosmo Labs app you can browse formulators and co-packers separately or find partners that do both, filtered by MOQ and capacity.