| Agonist | Source | Receptor(s) |
| Thrombin | End product of coagulation cascade | 7 transmembrane domain receptor |
| GPIb-alpha | ||
| Adenosine diphosphate | Platelet dense body | P2Y12 |
| Collagen | Subendothelium component | GPIa/IIa |
| GPIIb/IIIa | ||
| GPIV | ||
| Serotonin | Platelet dense body | 5HT2 receptor |
| Thromboxane A2 | Produced by platelets after initial stimulation | PGH2/TxA2 receptor |
| Platelet activating factor | Lipid mediator produced by other cells | PAF receptor |
