Pharmacodynamics
"What the drug does to the body" — the relationship between concentration and effect.
Pharmacodynamics (PD) describes the biochemical and physiological effects of a compound and its mechanism of action — receptor binding, downstream signalling, dose-response relationships, and the time course of effect. PD is the complement to pharmacokinetics: PK answers 'how much is there and for how long?', PD answers 'what does it do at that concentration?'. For research peptides, PD studies typically map dose-response curves in cell-culture and animal models, identifying potency, efficacy, and selectivity.
- GlossaryPhase 3
The penultimate stage of clinical drug development — large randomised trials testing efficacy and safety against existing standards of care.
- GlossaryPharmacokinetics
How the body absorbs, distributes, metabolises, and eliminates a compound — "what the body does to the drug."
- GlossaryIV vs IM vs SC
Three injection routes — intravenous, intramuscular, subcutaneous — with different absorption profiles.