subpotent
/sʌbˈpɒtnt/Definitions
1. adjective
having a power or effect that is less than normal or expected; insufficiently potent
“The new medication turned out to be subpotent, and it failed to relieve the patient’s symptoms.”
2. noun
a person or thing that is subpotent
“The company’s subpotent products have been affecting their overall sales.”