C
- Cabergoline
- Caffeine
- Camazepam
- Camfetamine
- Candesartan
- Candesartan cilexetil
- Cannabidiol
- Cannabigerol (CBG)
- Cannabinol
- Cannabis
- Canrenoic acid
- Canrenone
- Capsaicin
- Captopril
- Carazolol
- Carbamazepine
- Carbamazepine, 10, 11-dihydroxy
- Carbamazepine, 10-hydroxy
- Carbamazepine, 10-methoxy
- Carbamazepine, epoxide
- Carbaryl
- Carbendazim
- Carbetamide
- Carbimazole
- Carbodenafil
- Carbofuran
- Carbonyl-bromadol
- Carbosulfan
- Carbromal
- Carburazepam
- Carbutamide
- Carebastine
- Carfentanil
- Carfentanyl
- Carisoprodol
- Carpipramine
- Carteolol
- Carvedilol
- Cathine (Norpseudoephedrine; phenylpropanolamine)
- Cathinone
- CB-13
- CB-25
- CB-52
- CB-86
- CBL-018
- CBS-0550
- Cefaclor
- Cefadroxil
- Cefalexin
- Cefoperazone
- Cefotaxime
- Cefradine
- Ceftriaxone
- Cefuroxime
- Celecoxib
- Celiprolol
- Cephaeline
- Cephaeline (Emetine, desmethyl)
- Cerivastatin
- Cetirizine
- Cetirizine-M (N-desalkyl metabolite)
- Ciclotizolam
- Cilazapril
- Cimetidine
- Cimetidine-M (sulfoxide)
- Cinazepam
- Cinchonine
- Cinnarizine
- Cinolazepam
- Ciprofloxacin
- cis-3-Methyl butyryl fentanyl
- Cisapride
- Citalopram-M (desmethyl metabolite)
- Citalopram-M (didesmethy metabolite)
- Citalopram/Escitalopram
- Citicoline
- Cl-Pseudoephedrine
- Cl2201
- Clarithromycin
- Clazolam
- Clenbuterol
- Clenpenterol
- Climazolam
- Clindamycin
- Clindamycin phosphate
- Clobazam
- Clobazam, Desmethyl
- Clobenzorex
- Clobetasol propionate
- Clobromazolam
- Clodinafop-Propargyl
- Clofentezine
- Clomazone
- Clomethiazole
- Clomifene
- Clomipramine
- Clomipramine-M (N desmethyl metabolite)
- Clonazepam
- Clonazepam-M (7-acetamido)
- Clonazepam-M (7-amino metabolite)
- Clonazolam
- Clonidine
- Cloniprazepam
- Clonitazene
- Clopamide
- Clopidogrel
- Clothianidin
- Clothiapine
- Clotiazepam
- Clotrimazole
- Cloxacillin
- Cloxazolam
- Clozapine
- Clozapine-M (desmethyl metabolite)
- Clozapine-M (N-oxide metabolite)
- Cocaethylene
- Cocaine
- Cocaine, Nor
- Cocaine-M (hydroxy metabolite)
- Codeine
- Codeine, Glucuronide
- Codeine, Nor
- Codeine-D3
- Codethyline (Ethylmorphine)
- Colchicine
- Coluracetam
- Convallatoxin
- Corticosterone
- Cortisol
- Cortisone
- Cotinine
- Coumarin
- Coumatetralyl
- CP 55,244
- CP-47,497
- CP-47,497-C8-homolog
- CP-55,940
- CPCPP
- CPE
- CRA-13
- Creatine
- Crimidine
- Crotonyl Fentanyl
- Crotonylfentanyl
- CUMYL CBMICA
- CUMYL-5F-P7AICA
- Cumyl-BC-HpMeGaClone-221
- Cumyl-BICA
- Cumyl-Cb-MeGaClone
- CUMYL-CBEICA
- CUMYL-CBMICA
- CUMYL-CBMINACA
- Cumyl-CH-MeGaClone
- Cumyl-CHSINACA
- Cumyl-ClCHSINACA
- CUMYL-CPEICA
- Cumyl-CPMICA
- Cumyl-CPMINACA
- Cumyl-CPRMICA
- Cumyl-CPRMINACA
- Cumyl-INACA
- CUMYL-NBMICA
- CUMYL-NBMINACA
- Cumyl-PeGACLONE
- CUMYL-PICA
- CUMYL-PICA N-pentanoic acid metabolite
- CUMYL-PINACA
- CUMYL-PIPETINACA
- CUMYL-THPINACA
- CUMYL-TsINACA
- CYAMEMAZINE
- Cyanazine
- Cyclazodone
- Cyclizine
- Cyclobenzaprine
- Cyclobenzaprine-M (desmethyl metabolite)
- Cyclobutyl fentanyl
- Cyclobutylfentanyl
- Cyclohexalamine
- Cyclohexyl fentanyl
- Cyclohexylfentanyl
- Cyclopentenyl Fentanyl
- Cyclopenthiazide
- Cyclopentyl fentanyl
- Cyclopentylfentanyl
- Cyclopropane Acetyl Fentanyl
- Cyclopropyl fentanyl
- Cyclopropyl Norfentanyl
- Cyclopropyl U-47700
- Cyclopropylfentanyl
- Cyclopropylmescaline
- Cyclothiazide
- Cypermethrin
- Cyprazepam
- Cyproconazole
- Cyproheptadine
- Cyproterone acetate
- Cyromazine
- Cytarabine