As of July 18, 2026, Endomorphin-1 is legal to sell at retail in Massachusetts. Unscheduled - legal as research-use-only; no operative instrument reaches a structurally-dissimilar opioid peptide. Controlling source: M.G.L. c. 94C 1 (controlled substance analogue).
Verified July 18, 2026 · confidence: confirmedEndomorphin-1 (Tyr-Pro-Trp-Phe-NH2) is not named or scheduled in Massachusetts. The state has a controlled-substance analogue statute whose similarity test is CONJUNCTIVE (chemical structure substantially similar to a scheduled substance AND a substantially similar CNS effect). The structure prong fails for a tetrapeptide, so the statute does not reach EM-1. Controlling instrument reviewed: M.G.L. c. 94C 1 (controlled substance analogue). Conclusion: no operative instrument reaches a structurally-dissimilar endogenous opioid peptide; status LEGAL at the state controlled-substances level. Residual risk: minimal. Federal floor still applies (Analogue Act human-consumption contingency + FD&C unapproved-new-drug).
M.G.L. c. 94C 1: a "drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E ... AND which has a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than ..." [Conjunctive - structure prong fails.]
Among Massachusetts's 5 neighbors, Connecticut, New Hampshire, New York, Rhode Island and Vermont are legal, the same posture as Massachusetts.
Open the interactive map · Every compound in Massachusetts
Not federally scheduled. Endomorphin-1 - not federally scheduled; endogenous opioid tetrapeptide, no CSA entry and no analogue-act structural hook Federal detail
3 instruments on file for this compound's framework in Massachusetts; 2 of 2 citations above are official sources. Each text carries its source and a fingerprint that changes when the law does.
bb9414240b38bb19**Schedule gap — § 31, Class C(e):** "Unless specifically excepted or listed in another schedule, any material, compound, mixture, or preparation, which contains any quantity of the following hallucinogenic substances, or which contains any of their salts, isomers, and salts of isomers whenever the existence of such salts, isomers, and salts of isomers is possible … (13) Psilocybin (14) Psilocyn …" (4-HO-MET not named; isomer-only catch-all does not reach a homolog.) — M.G.L. c. 94C § 31, official: https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXV/Chapter94C/Section31 **Analog definition — c. 94C § 1:** "'Controlled substance analogue', (i) a drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E, listed in section 31 and which has a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than [that] of a controlled substance in Class A, B, C, D or E … provided, however, that for the purposes of this chapter, a 'controlled substance analogue' shall be treated as the Class A, B, C, D or E substance of which it is a controlled substance analogue." And: "'Controlled substance', a drug, substance, controlled substance analogue or immediate precursor …" — M.G.L. c. 94C § 1, official: https://malegislature.gov/Laws/GeneralLaws/PartI/TitleXV/Chapter94C/Section1
9a0f4c5c022d2a01Section 1. As used in this chapter, the following words shall, unless the context clearly requires otherwise, have the following meanings: "Controlled substance", a drug, substance, controlled substance analogue or immediate precursor in any schedule or class referred to in this chapter. "Controlled substance analogue", (i) a drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E, listed in section 31 and which has a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than the stimulant, depressant or hallucinogenic effect on the central nervous system of a controlled substance in Class A, B, C, D or E, listed in said section 31; or (ii) a drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E, listed in said section 31 and with respect to a particular person, which such person represents or intends to have a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than the stimulant, depressant or hallucinogenic effect on the central nervous system of a controlled substance in Class A, B, C, D or E, listed in said section 31; provided, however, that "controlled substance analogue" shall not include: (1) a controlled substance; (2) any substance for which there is an approved new drug application; (3) with respect to a particular person, any substance for which there is an exception in effect for investigational use for that person, under section 8, to the extent conduct with respect to the substance is pursuant to such exemption; or (4) any substance not intended for human consumption before such an exemption takes effect with respect to that substance; provided, however, that for the purposes of this chapter, a "controlled substance analogue" shall be treated as the Class A, B, C, D or E substance of which it is a controlled substance analogue. "Marihuana", all parts of the plant Cannabis sativa L., whether growing or not; the seeds thereof; and resin extracted from any part of the plant; and every compound, manufacture, salt, derivative, mixture, or preparation of the plant, its seeds or resin. It does not include the mature stalks of the plant, industrial hemp as defined in section 116 of chapter 128, fiber produced from the stalks, oil, or cake made from the seeds of the plant, any other compound, manufacture, salt, derivative, mixture, or preparation of the mature stalks, except the resin extracted therefrom, fiber, oil, or cake or the sterilized seed of the plant which is incapable of germination. "Tetrahydrocannabinol", tetrahydrocannabinol or preparations containing tetrahydrocannabinol excluding marihuana except when it has been established that the concentration of delta-9 tetrahydrocannabinol in said marihuana exceeds two and one-half per cent.
96ef8a86f5adb52c''Controlled substance analogue'', (i) a drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E, listed in section 31 and which has a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than the stimulant, depressant or hallucinogenic effect on the central nervous system of a controlled substance in Class A, B, C, D or E, listed in said section 31; or (ii) a drug or substance with a chemical structure substantially similar to the chemical structure of a controlled substance in Class A, B, C, D or E, listed in said section 31 and with respect to a particular person, which such person represents or intends to have a stimulant, depressant or hallucinogenic effect on the central nervous system that is substantially similar to or greater than the stimulant, depressant or hallucinogenic effect on the central nervous system of a controlled substance in Class A, B, C, D or E, listed in said section 31; provided, however, that ''controlled substance analogue'' shall not include: (1) a controlled substance; (2) any substance for which there is an approved new drug application; (3) with respect to a particular person, any substance for which there is an exception in effect for investigational use for that person, under section 8, to the extent conduct with respect to the substance is pursuant to such exemption; or (4) any substance not intended for human consumption before such an exemption takes effect with respect to that substance; provided, however, that for the purposes of this chapter, a ''controlled substance analogue'' shall be treated as the Class A, B, C, D or E substance of which it is a controlled substance analogue.
Compound Laws, published by Compound Analytics, reports the record: statutes verbatim, official citations, enforcement facts and verification dates. Nothing here is legal advice and nothing here describes how to get around a law. A jurisdiction with no verified row is reported as not yet verified, never as legal. Found an error? Corrections policy.
About · Methodology · Glossary · Changes · Data & API · llms.txt · Sitemap