Hello Bio launches water soluble Compound 21 (DREADD agonist 21)

Hello Bio launches water soluble Compound 21 (DREADD agonist 21)

09 Aug 2017

DREADD receptorsHello Bio announced today the launch of water soluble Compound 21 (DREADD agonist 21) – an exciting tool for scientists studying GPCR signaling, and a useful alternative to clozapine N-oxide (CNO).

GPCRs can be modified so that they only respond to a specific biologically inert chemical (a designer drug). These modified GPCRs are called Designer Receptors Exclusively Activated by Designer Drugs or “DREADDs”. Cells expressing DREADDs respond robustly to low concentrations of the designer molecule, whereas cells that do not express DREADD are unresponsive to the designer drug. 

A recent publication in Science has reported that the traditionally used DREADD agonist clozapine N-oxide may have more off-target effects in vivo, than previously thought. Therefore pharmacological tools that offer additional ways to investigate DREADDs are of great use to researchers in this field.

Water-soluble Compound 21 (DREADD agonist 21) can be used as an alternative to clozapine N-oxide (water soluble), or to supplement CNO studies. Compound 21 has a similar in vivo potency to CNO, but is less likely to metabolize to clozapine. It offers another option for researchers studying DREADDs. And of course, in keeping with our ethos – it is offered at a very low price.

Steve Roome PhD, Managing Director and Founder, Hello Bio

Water soluble Compound 21 (DREADD agonist 21) joins a range of affordable and high quality tools for GPCR and DREADDs research, including DREADD ligands clozapine N-oxide and salvinorin B, and the novel GRK2/3 inhibitor Cmpd101, that can be used to study GPCR desensitisation.


For more information, please contact
Steve Roome:
(0)117 3180 505

Further information

For full details of the Science publication, see: Gomez et al., Science 357, 503–507 (2017) Chemogenetics revealed: DREADD occupancy and activation via converted clozapine

Hello Bio was founded by a team of experienced scientists and chemists who genuinely want to support life science research. Our aim is to offer a range of high quality life science tools at prices so low that as many researchers as possible will be able to afford them.

We offer a range of agonists, antagonists, inhibitors, activators, antibodies and fluorescent tools at up to half the price of other suppliers. The range includes:


We also offer a cost effective custom synthesis service for customers requiring specialist tools, or bulk quantities.