Since 2009, some groups of NPS have been brought under control using a generic approach. For instance, synthetic cannabinoids such as phenylacetylindoles were placed under control using the generic approach in 2009. A group of substituted piperazines (mCPP; pCPP; pFPP; TFMPP; mMPP; pMPP; pMeOPP; CPCPP; DBZP; and BZMP) were also subsumed in the generic definition (see The Misuse of Drugs Act 1971 (Amendment) Order 2009 No. 3209).
Other cathinone derivatives were placed under control as Class B drugs in 2010 (see The Misuse of Drugs Act 1971 (Amendment) Order 2010 No. 1207).
A further group of cathinone derivatives (including naphthylpyrovalerone -among this naphyrone-) was placed under control by adding them to the list of Class B drugs under the Misuse of Drugs Act (see The Misuse of Drugs Act 1971 (Amendment No. 2) Order 2010 No. 1833).
New categories of synthetic cannabinoids and other NPS related to ketamine and phencyclidine-type substances were placed under control in 2013 (see The Misuse of Drugs Act 1971 (Amendment) Order 2013 No. 239).
Groups of NBOMe compounds (some of which were subject to control under a Temporary Class Drug Order (SI 2013/1294)) were brought under permanent control as Class A drugs, groups of benzofuran compounds were placed under permanent control as Class B drugs (some of which were subject to control under a Temporary CDO ((SI 2013/1294)) in 2014 (see The Misuse of Drugs Act 1971 (Ketamine etc.) (Amendment) Order 2014 No. 1106).
had a generic definition as "Class A" drugs introduced from 15 January 2025, by amending the Misuse of Drugs Act 1971 (see and ) as follows:
“any compound with a maximum molecular mass of 500 atomic mass units and structurally derived from 2-(2-benzyl-benzimidazol-1-yl)ethanamine by modification in any of the following ways, that is to say—
(i)by substitution at the nitrogen of the ethanamine to any extent by alkyl substituents containing up to three carbon atoms or alkenyl substituents containing up to three carbon atoms or by inclusion of the nitrogen atom (and no other atoms of the side chain) in a cyclic structure;
(ii)by substitution in the phenyl ring of the benzyl system to any extent by alkyl or haloalkyl containing up to six carbon atoms, alkoxy or haloalkoxy containing up to five carbon atoms, acetyloxy, hydroxy, cyano, halogen, thioalkyl containing up to five carbon atoms or alkylsulphonyl containing up to five carbon atoms;
(iii)by substitution at the 5- or 6- positions of the benzimidazole system by nitro, acetyl, cyano, methoxy, trifluoromethyl, trifluoromethoxy or halogen substituents;
(iv)by substitution at the benzylic carbon by a methyl group;
(v)by replacement of the benzylic carbon by a nitrogen, oxygen or sulphur atom;
(vi)by substitution in the phenyl ring of the benzyl system by an ethoxy group linked back to the phenyl ring to form a dihydrobenzofuran structure;
(vii)by replacement of the phenyl ring of the benzyl system by methylenedioxyphenyl.”
A further amendment was announced on 29 January 2025 to undergo further consultation.