25-nb 25-nb the 25-nb (25x-nbx) series, sometimes alternatively referred to as the nbome compounds, is a family of serotonergic psychedelics. they are substituted phenethylamines and were derived from the 2c family. they act as selective agonists of the serotonin 5-ht2a receptor. the 25-nb family is unique relative to other classes of psychedelics in that they are, generally speaking, extremely potent and relatively selective for the 5-ht2a receptor. use of nbome series drugs has caused many deaths and hospitalisations since the drugs popularisation in the 2010s. this is primarily due to their high potency, unpredictable pharmacokinetics, and sellers passing off the compounds in the series as lsd. 25i-nbome, the most well-known 25-nb derivative chemical structure the 25-nb compounds are mostly n-benzylphenethylamines, though in some cases the phenyl ring of the n-benzyl group is replaced by other heterocycles such as thiophene, pyridine, furan, tetrahydrofuran, benzodioxole or naphthalene, among others. generally speaking, they have methoxy groups at the 2 and 5 positions of the phenyl ring, a substitution such as a halogen or alkyl group at the 4 position of the phenyl ring, and a methoxy or other substitution (e.g., hydroxyl, fluoro) at the 2 position of the n-benzyl ring. more rarely, other substitution patterns may be present (see e.g. nbome-mescaline, 25g-nbome, 2cbfly-nbome, 25c-nb3ome). they differ from the 2c series by the presence of the n-benzyl moiety. rarely an alpha-methyl group is present making them n-benzyl amphetamines rather than n-benzyl phenethylamines, but this greatly reduces potency and activity. however in some cases where a side chain methyl group is cyclised back to the ring (e.g. in 2cbcb-nbome) or links the two alpha positions (e.g. in dmbmpp), this can improve selectivity for the 5-ht2a receptor subtype. list of 25-nb derivatives general structure of 25-nb derivatives, where r is usually 2,5-dimethoxy-4-(alkyl or halogen), r1 is usually h but rarely methyl, and cyc is usually 2-substituted phenyl but can be other heterocycles. this list includes notable compounds representative of most of the structural variations that have been explored in this series, but is by no means exhaustive. many derivatives invented for scientific study into the structure-activity relationships of 5-ht2 receptor agonists have never appeared as designer drugs, while conversely some derivatives that have appeared as designer drugs are structurally novel and of unknown pharmacological activity (e.g. c30-nbome, 5-apb-nbome). chemical structure common name chemical name cas number r r1 cyc 25b-nb n-benzyl-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 155639-26-2 2,5-dimethoxy-4-bromo h phenyl 25c-nb n-benzyl-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1391487-65-2 2,5-dimethoxy-4-chloro h phenyl 25i-nb n-benzyl-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 919797-18-5 2,5-dimethoxy-4-iodo h phenyl 25i-nmeth n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1391499-03-8 2,5-dimethoxy-4-iodo h thiophen-2-yl 25b-nmepyr n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391499-21-0 2,5-dimethoxy-4-bromo h pyridin-2-yl 25i-nmefur n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1391498-93-3 2,5-dimethoxy-4-iodo h furan-2-yl 25i-nmethf n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 2,5-dimethoxy-4-iodo h tetrahydrofuran-2-yl 25b-nbf n-(2-fluorobenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1539266-17-5 2,5-dimethoxy-4-bromo h 2-fluorophenyl 25b-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1335331-46-8 2,5-dimethoxy-4-bromo h 2-hydroxyphenyl 25b-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1026511-90-9 2,5-dimethoxy-4-bromo h 2-methoxyphenyl 25b-nb23dm n-(2,3-dimethoxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391493-68-7 2,5-dimethoxy-4-bromo h 2,3-dimethoxyphenyl 25b-nb25dm n-(2,5-dimethoxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 2,5-dimethoxy-4-bromo h 2,5-dimethoxyphenyl 25b-nme7bf n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391492-46-8 2,5-dimethoxy-4-bromo h benzofuran-7-yl 25b-nme7dhbf n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391492-40-2 2,5-dimethoxy-4-bromo h 2,3-dihydrobenzofuran-7-yl 25b-nme7bt n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391492-59-3 2,5-dimethoxy-4-bromo h benzothiophen-7-yl 25b-nme7box n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391498-73-9 2,5-dimethoxy-4-bromo h benzoxazol-7-yl 25b-nme7ind n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391498-28-4 2,5-dimethoxy-4-bromo h indol-7-yl 25b-nme7indz n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391498-43-3 2,5-dimethoxy-4-bromo h indazol-7-yl 25b-nme7bim n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1391498-62-6 2,5-dimethoxy-4-bromo h benzimidazol-7-yl fecimbi-36 n--1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 2,5-dimethoxy-4-bromo h 2-(2-fluoroethoxy)phenyl dob-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminopropane 2,5-dimethoxy-4-bromo methyl 2-methoxyphenyl 25c-nb3ome n-(3-methoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1566571-34-3 2,5-dimethoxy-4-chloro h 3-methoxyphenyl 25c-nb4ome n-(4-methoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1566571-35-4 2,5-dimethoxy-4-chloro h 4-methoxyphenyl c30-nbome n-(3,4,5-trimethoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1445574-98-0 2,5-dimethoxy-4-chloro h 3,4,5-trimethoxyphenyl 25c-nbf n-(2-fluorobenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1539266-21-1 2,5-dimethoxy-4-chloro h 2-fluorophenyl 25c-nbcl n-(2-chlorobenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 2,5-dimethoxy-4-chloro h 2-chlorophenyl 25c-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1391488-16-6 2,5-dimethoxy-4-chloro h 2-hydroxyphenyl 25c-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1227608-02-7 2,5-dimethoxy-4-chloro h 2-methoxyphenyl 25c-nboet n-(2-ethoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 2,5-dimethoxy-4-chloro h 2-ethoxyphenyl 25c-nboipr n-(2-isopropoxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 2,5-dimethoxy-4-chloro h 2-isopropoxyphenyl 25f-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-fluorophenyl)-2-aminoethane 1373917-84-0 2,5-dimethoxy-4-fluoro h 2-methoxyphenyl 25cn-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-cyanophenyl)-2-aminoethane 1539266-32-4 2,5-dimethoxy-4-cyano h 2-hydroxyphenyl 25cn-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-cyanophenyl)-2-aminoethane 1354632-16-8 2,5-dimethoxy-4-cyano h 2-methoxyphenyl 25d-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-methylphenyl)-2-aminoethane 1354632-02-2 2,5-dimethoxy-4-methyl h 2-methoxyphenyl 25d-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-methylphenyl)-2-aminoethane 1391488-44-0 2,5-dimethoxy-4-methyl h 2-hydroxyphenyl 25e-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-ethylphenyl)-2-aminoethane 1354632-14-6 2,5-dimethoxy-4-ethyl h 2-methoxyphenyl 25e-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-ethylphenyl)-2-aminoethane 1391489-79-4 2,5-dimethoxy-4-ethyl h 2-hydroxyphenyl 25g-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-3,4-dimethylphenyl)-2-aminoethane 1354632-65-7 2,5-dimethoxy-3,4-dimethyl h 2-methoxyphenyl 25h-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxyphenyl)-2-aminoethane 1566571-52-5 2,5-dimethoxy h 2-methoxyphenyl 25i-nb34md n-(3,4-methylenedioxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1391497-81-6 2,5-dimethoxy-4-iodo h 3,4-methylenedioxyphenyl 25i-nb3ome n-(3-methoxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1566571-40-1 2,5-dimethoxy-4-iodo h 3-methoxyphenyl 25i-nb4ome n-(4-methoxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1566571-41-2 2,5-dimethoxy-4-iodo h 4-methoxyphenyl 25i-nbf n-(2-fluorobenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 919797-21-0 2,5-dimethoxy-4-iodo h 2-fluorophenyl 25i-nbbr n-(2-bromobenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1648649-98-2 2,5-dimethoxy-4-iodo h 2-bromophenyl 25i-nbtfm n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 2,5-dimethoxy-4-iodo h 2-(trifluoromethyl)phenyl 25i-nbmd n-(2,3-methylenedioxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 919797-25-4 2,5-dimethoxy-4-iodo h 2,3-methylenedioxyphenyl 25b-nbmd n-(2,3-methylenedioxybenzyl)-1-(2,5-dimethoxy-4-bromophenyl)-2-aminoethane 1354632-19-1 2,5-dimethoxy-4-bromo h 2,3-methylenedioxyphenyl 25c-nbmd n-(2,3-methylenedioxybenzyl)-1-(2,5-dimethoxy-4-chlorophenyl)-2-aminoethane 1373879-26-5 2,5-dimethoxy-4-chloro h 2,3-methylenedioxyphenyl 25d-nbmd n-(2,3-methylenedioxybenzyl)-1-(2,5-dimethoxy-4-methylphenyl)-2-aminoethane 1391488-97-3 2,5-dimethoxy-4-methyl h 2,3-methylenedioxyphenyl 25i-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 919797-20-9 2,5-dimethoxy-4-iodo h 2-hydroxyphenyl 25i-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 919797-19-6 2,5-dimethoxy-4-iodo h 2-methoxyphenyl doi-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane 2,5-dimethoxy-4-iodo methyl 2-methoxyphenyl 25i-nbmeoh n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1391494-71-5 2,5-dimethoxy-4-iodo h 2-(hydroxymethyl)phenyl 25i-nbam n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1391494-85-1 2,5-dimethoxy-4-iodo h 2-(carbamoyl)phenyl 25i-nme7dhbf n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 2,5-dimethoxy-4-iodo h 2,3-dihydrobenzofuran-7-yl 25i-n2nap1oh n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 2,5-dimethoxy-4-iodo h 1-hydroxynaphthalen-2-yl 25i-n3mt2m n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1354632-66-8 2,5-dimethoxy-4-iodo h 3-methoxythiophen-2-yl 25i-n4mt3m n--1-(2,5-dimethoxy-4-iodophenyl)-2-aminoethane 1354632-73-7 2,5-dimethoxy-4-iodo h 4-methoxythiophen-3-yl 25ip-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-isopropylphenyl)-2-aminoethane 1391487-83-4 2,5-dimethoxy-4-isopropyl h 2-methoxyphenyl 25n-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-nitrophenyl)-2-aminoethane 1354632-03-3 2,5-dimethoxy-4-nitro h 2-methoxyphenyl 25n-nboet n-(2-ethoxybenzyl)-1-(2,5-dimethoxy-4-nitrophenyl)-2-aminoethane 2,5-dimethoxy-4-nitro h 2-ethoxyphenyl 25n-nb-2-oh-3-me n-(2-hydroxy-3-methylbenzyl)-1-(2,5-dimethoxy-4-nitrophenyl)-2-aminoethane 2,5-dimethoxy-4-nitro h 2-hydroxy-3-methylphenyl 25n-nbocf2h n-(2-difluoromethoxybenzyl)-1-(2,5-dimethoxy-4-nitrophenyl)-2-aminoethane 2,5-dimethoxy-4-nitro h 2-difluoromethoxyphenyl 25p-nbome n-(2-methoxybenzyl)-1-(2,5-dimethoxy-4-propylphenyl)-2-aminoethane 1391489-07-8 2,5-dimethoxy-4-propyl h 2-methoxyphenyl 25p-nboh n-(2-hydroxybenzyl)-1-(2,5-dimethoxy-4-propylphenyl)-2-aminoethane 1391490-34-8 2,5-dimethoxy-4-propyl h 2-hydroxyphenyl 25tfm-nbome n-(2-methoxybenzyl)-1--2-aminoethane 1027161-33-6 2,5-dimethoxy-4-(trifluoromethyl) h 2-methoxyphenyl 25o-nbcpr n-(2-cyclopropylbenzyl)-1-(2,4,5-trimethoxyphenyl)-2-aminoethane 2,4,5-trimethoxy h 2-cyclopropylphenyl 25t-nbome n-(2-methoxybenzyl)-1--2-aminoethane 1539266-47-1 2,5-dimethoxy-4-(methylthio) h 2-methoxyphenyl 25t2-nbome n-(2-methoxybenzyl)-1--2-aminoethane 1539266-51-7 2,5-dimethoxy-4-(ethylthio) h 2-methoxyphenyl 25t4-nbome n-(2-methoxybenzyl)-1--2-aminoethane 1354632-17-9 2,5-dimethoxy-4-(isopropylthio) h 2-methoxyphenyl 25t7-nbome n-(2-methoxybenzyl)-1--2-aminoethane 1539266-55-1 2,5-dimethoxy-4-(propylthio) h 2-methoxyphenyl 25t7-nboh n-(2-hydroxybenzyl)-1--2-aminoethane 1354632-41-9 2,5-dimethoxy-4-(propylthio) h 2-hydroxyphenyl 25am-nbome n-(2-methoxybenzyl)-1--2-aminoethane 2,5-dimethoxy-4-(n-pentyl) h 2-methoxyphenyl nbome-mescaline n-(2-methoxybenzyl)-1-(3,4,5-trimethoxyphenyl)-2-aminoethane 1354632-01-1 3,4,5-trimethoxy h 2-methoxyphenyl nbome-escaline n-(2-methoxybenzyl)-1-(3,5-dimethoxy-4-ethoxyphenyl)-2-aminoethane 3,5-dimethoxy-4-ethoxy h 2-methoxyphenyl nbome-thiobuscaline n-(2-methoxybenzyl)-1-(3,5-dimethoxy-4-butylthiophenyl)-2-aminoethane 3,5-dimethoxy-4-(n-butylthio) h 2-methoxyphenyl mdpea-nbome n-(2-methoxybenzyl)-1-(3,4-methylenedioxyphenyl)-2-aminoethane 3,4-methylenedioxy h 2-methoxyphenyl mdbz n-benzyl-1-(3,4-methylenedioxyphenyl)-2-aminopropane 65033-29-6 3,4-methylenedioxy methyl phenyl clobenzorex n-(2-chlorobenzyl)-1-phenyl-2-aminopropane 13364-32-4 h methyl 2-chlorophenyl 4-ea-nbome n-(2-methoxybenzyl)-1-(4-ethylphenyl)-2-aminopropane 4-ethyl methyl 2-methoxyphenyl 5-apb-nbome n-(2-methoxybenzyl)-1-(benzofuran-5-yl)-2-aminopropane benzofuran-5-yl instead of phenyl methyl 2-methoxyphenyl similar compounds with related structures are also known including; chemical structure common name chemical name cas number 25b-n1pome n--2,5-dimethoxy-4-bromophenethylamine 1335331-49-1 (r)1335331-51-5 (s) 2c-b-an 2-phenyl-2-acetonitrile 25b-n(bome)2 2-(4-bromo-2,5-dimethoxyphenyl)-n,n-bis(2-methoxybenzyl)ethan-1-amine 2cbcb-nbome n-octa-1,3,5-trien-7-yl)methyl]-1-(2-methoxyphenyl)methanamine 1354634-09-5 2cbfly-nbome n-(2-methoxybenzyl)-1-(8-bromo-2,3,6,7-tetrahydrobenzodifuran-4-yl)-2-aminoethane 1335331-42-4 2c-b-dragonfly-nboh n-(2-hydroxybenzyl)-1-(8-bromobenzodifuran-4-yl)-2-aminoethane 1335331-45-7 2c-b-fly-nb2eto5cl n-(2-ethoxy-5-chlorobenzyl)-1-(8-bromo-2,3,6,7-tetrahydrobenzodifuran-4-yl)-2-aminoethane dmbmpp (s,s)-2-(2,5-dimethoxy-4-bromobenzyl)-6-(2-methoxyphenyl)piperidine 1391499-52-7 25b-nacpip 2--1-(piperidin-1-yl)ethanone zdcm-04 1,3-dimethyl-7-purine-2,6-dione rh-34 3--1h-quinazoline-2,4-dione 1028307-48-3 5mt-nbome n-(2-methoxybenzyl)-5-methoxytryptamine 1335331-37-7 5mt-nb3ome n-(3-methoxybenzyl)-5-methoxytryptamine 1648553-42-7 legality united kingdom a large number of substances in the 25-nb class are class a drugs in the united kingdom as a result of the n-benzylphenethylamine catch-all clause in the misuse of drugs act 1971 or are otherwise covered by the psychoactive substances act 2016.