S
- S-22 (Ostarine)
- S-23
- S-4 (Andarine)
- Salbutamol
- Salicylamide
- Salmeterol
- Salvinorin A
- Salvinorin B
- Saquinavir
- Scopolamine
- SDB-005
- SDB-006
- SDB-006-N-Phenyl
- Sebuthylazine
- sec-Butonitazene
- Secbumeton
- Secnidazole
- Secobarbital
- Selegiline
- Senecioyl Fentanyl
- SER-601
- Sertindol
- Sertindole-M (dehydro metabolite)
- Sertraline
- Sethoxydim
- SGT-13
- SGT-235
- Sibutramine
- Sibutramine, Desmethyl
- Sibutramine, Didesmethyl
- sibutramine-Nor
- Siduron
- Sildenafil
- Sildenafil, desmethyl
- Sildenafil, dimethyl (Aildenafil)
- Simazine
- Simetryn
- Simvastatin
- Sitaglipin
- SL-164
- SL-651,498
- Solifenacin
- Sotalol
- Sparteine
- Spiramycin
- Spiromesifen
- Spironolactone
- Spiroxamine
- Stanozolol
- Stanozolol acetate
- Stanozolol-M (16-beta-hydroxy metabolite)
- Stanozolol-M (3-hydroxy metabolite)
- Stanozolol-M (3-hydroxy-glucuronide metabolite)
- Stanozolol-M (4-en metabolite)
- Stavudine
- Stenbolone
- Streptomycin
- Strychnine
- STS-135
- STS-135 (4-OH-Pentyl)
- STS-135 (5F-APICA)
- Sufentanil
- Sulazepam
- Sulcotrione
- Sulfadoxine
- Sulfamethoxazole
- Sulfapyridine
- Sulfaquinoxaline
- Sulfasalazine
- Sulfometuron-methyl
- Sulfotep
- Sulindac
- Sulpiride
- Sultiame
- Sultopride
- Sumatriptan
- Sunifiram
- Synephrine