Difelikefalin (CR-845; FE-202845) acetate is a peripherally restricted and selective agonist of kappa opioid receptor (KOR). Difelikefalin acetate produces anti-inflammatory effects and has the potential in modulating pruritus in conditions such as chronic kidney disease.

DH-1-106 is a MOR partial agonist. DH-1-106 can be used in the study of analgesia.

DBPR116 is a prodrug of BPRMU191 with blood-brain barrier penetration capability. DBPR116 significantly improves the delivery of centrally targeted drugs. In combination with the antagonist Naltrexone, DBPR116 demonstrated superior safety and analgesic efficacy compared to morphine in various in vivo pharmacological studies, including thermal pain models, cancer pain models, constipation, sedation, psychological dependence, heart rate, and respiratory frequency. As a prodrug strategy for peripheral administration, DBPR116 effectively alleviates pain while reducing adverse effects, showing potential as a safer opioid analgesic.

Cyprodime is a selective μ opioid receptor (MOR) antagonist with Kis of 5.4, 244.6, and 2187 nM for μ, δ, and κ, respectively.

Chlorphine is a neuroactive halogenated opioid analog.

Cebranopadol hemicitrate is an analgesic NOP and opioid receptor agonist with Kis/EC50s of 0.9 nM/13 nM, 0.7 nM/1.2 nM, 2.6 nM/17 nM, 18 nM/110 nM for human NOP, MOP, KOP and delta-opioid peptide (DOP) receptor, respectively. Cebranopadol hemicitrate can be used for acute and chronic pain study.

BU72 is a highly potent and long-acting agonist of μ and κ opioid receptors, and also has a partial agonist effect on δ opioid receptors (EC50 values are 0.054, 0.033, and 0.58 nM, respectively). BU72 has a strong and long-lasting analgesic effect, which is mainly mediated by μ opioid receptors. BU72 has a long-lasting activity and can partially reverse the analgesic effect of morphine. BU72 can be used in the study of opioid dependence.

Bromadoline is a utopioid with antinociceptive activity in rodents.

Bromadol is an opioid.

BPRMU191 is a μ-opioid receptor (MOR) modulator that converts small-molecule morphinan antagonists into G protein-biased MOR agonists, thereby inducing MOR-dependent activation and analgesic effects. Co-administration of BPRMU191 with morphinan antagonists provides analgesia while reducing side effects such as gastrointestinal dysfunction, antinociceptive tolerance, and dependency-related adverse effects. BPRMU191, in combination with morphinan antagonists, offers a potential strategy for studying severe pain management and G protein-coupled receptor modulation.

BNTX (7-Benzylidenenaltrexone) maleate is a δ1-opioid receptor antagonist with the Kis of 0.1, 10.8, 13.3, and 58.6 nM for δ1, δ2-, μ-, and κ-opioid receptor, respectively. BNTX maleate shows antinociceptive activity.

Bipiperidinyl 4-ANPP is structurally similar to known opioids.

AZ 12488024 (AZD7268) is a SNC80.

AP-238 is a a new synthetic opioid (NSO), and acts as an agonist for μ-opioid receptor (MOR) with an EC50 of 248 nM. AP-238 exhibits analgesic activity.

Alvimopan metabolite hydrochloride is a peripherally restricted Opioid Receptor antagonist that inhibits the amplitude of electrically evoked contractions and spontaneous mechanical activity in guinea pig ileum.

Allyphenyline oxalate (compound 9) can enhance the analgesic effect of Morphine. The pKi values ​​of Allyphenyline for α2A, α2B and α2C are 7.24, 6.47 and 7.07, respectively.

AH-8533 is a opioid agent.

AH 7959 is an orally active N-substituted cyclohexyl methyl benzamide compound that has analgesic effects, the oral and subcutaneous ED50 of AH 7959 in mice is greater than 1 g/kg.

5′-Guanidinonaltrindole (GNTI) is a selective kappa opioid receptor antagonist.

3-Carboxamidonaltrexone (example 32) is a opioid receptor binding compound with Ki values of 1.9 nM, 110 nM, and 22 nM for μ-opioid receptor, δ-opioid receptor, and K-opioid receptor, respectively.

3,4-Difluoro U-50488 hydrochloride is a utopioid.

3,4-Difluoro propyl U-47700 is a utopioid.

3,4-Difluoro isopropyl U-47700 is a utopioid.

2-Naphthyl U-47700 is a utopioid.

2,4-Difluoro U-48800 hydrochloride is a utopioid.

(S)-MCOPPB is the S-form of MCOPPB.

(+)-Norpropoxyphene maleate is an opioid metabolite and is a metabolite of Propoxyphene.

(-)-9-Hydroxycorynantheidine (9-O-Desmethyl mitragynine), the 9-demethyl analogue of Mitragynine, is a selective and partial agonist of μ-opioid receptor. (-)-9-Hydroxycorynantheidine inhibits electrically stimulated twitch contraction in guinea-pig ileum.

(Rac)-SNC80 is a racemate of SNC80. SNC80 (NIH 10815) is a potent, highly selective and non-peptide δ-opioid receptor agonist with a Ki of 1.78 nM and an IC50 of 2.73 nM. SNC80 shows antinociceptive, antihyperalgesic and antidepressant‐like effects. SNC80 has the potential for multiple headache disorders treatment.

LY2940094 (BTRX-246040) tartrate is a potent, brain penetrant, selective and orally available N/OFQ peptide (NOP) receptor antagonist with high affinity (Ki=0.105 nM) and antagonist potency (Kb=0.166 nM). LY2940094 tartrate reduces Ethanol self-administration and Ethanol seeking in animal models.