Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Clinical Trial
. 2023 May;48(3):311-327.
doi: 10.1007/s13318-023-00822-y. Epub 2023 Apr 22.

Pharmacokinetics of N,N-dimethyltryptamine in Humans

Meghan Good  1 , Zelah Joel  2 , Tiffanie Benway  2 , Carol Routledge  2 , Chris Timmermann  3 , David Erritzoe  3 , Richard Weaver  4 , Graham Allen  5 , Charlotte Hughes  6 , Helen Topping  6 , Amy Bowman  7 , Ellen James  2
Affiliations
Clinical Trial

Pharmacokinetics of N,N-dimethyltryptamine in Humans

Meghan Good et al. Eur J Drug Metab Pharmacokinet. 2023 May.

Abstract

Background and objective: N,N-dimethyltryptamine (DMT) is a psychedelic compound under development for the treatment of major depressive disorder (MDD). This study evaluated the preclinical and clinical pharmacokinetics and metabolism of DMT in healthy subjects.

Methods: The physiochemical properties of DMT were determined using a series of in vitro experiments and its metabolic profile was assessed using monoamine oxidase (MAO) and cytochrome P450 (CYP) inhibitors in hepatocyte and mitochondrial fractions. Clinical pharmacokinetics results are from the phase I component of a phase I/IIa randomised, double-blind, placebo-controlled, parallel-group, dose-escalation trial (NCT04673383). Healthy adults received single escalating doses of DMT fumarate (SPL026) via a two-phase intravenous (IV) infusion. Dosing regimens were calculated based on pharmacokinetic modelling and predictions with progression to each subsequent dose level contingent upon safety and tolerability.

Results: In vitro clearance of DMT was reduced through the inhibition of MAO-A, CYP2D6 and to a lesser extent CYP2C19. Determination of lipophilicity and plasma protein binding was low, indicating that a high proportion of DMT is available for distribution and metabolism, consistent with the very rapid clinical pharmacokinetics. Twenty-four healthy subjects received escalating doses of DMT administered as a 10-min infusion over the dose range of 9-21.5 mg (DMT freebase). DMT was rapidly cleared for all doses: mean elimination half-life was 9-12 min. All doses were safe and well tolerated and there was no relationship between peak DMT plasma concentrations and body mass index (BMI) or weight.

Conclusion: This is the first study to determine, in detail, the full pharmacokinetics profile of DMT following a slow IV infusion in humans, confirming rapid attainment of peak plasma concentrations followed by rapid clearance. These findings provide evidence which supports the development of novel DMT infusion regimens for the treatment of MDD.

Clinical trial registration: Registered on ClinicalTrials.gov (NCT04673383).

PubMed Disclaimer

Conflict of interest statement

M.G., T.B., Z.J., C.R. and E.J. are all currently paid employees of Small Pharma and have owned stock in the company, C.T., D.E., G.A., R.W., C.H., H.T. and A.B., are all paid employees of contracted research and academic organisations or independent consultants engaged by Small Pharma.

Figures

Fig. 1
Fig. 1
Mean plasma concentration-time profiles for DMT on a (A) linear and (B) logarithmic scale for all dose cohorts of DMT.  DMT N,N-dimethyltryptamine
Fig. 2
Fig. 2
Cmax (A) and AUClast (B) for all doses of DMT. Linear regression equations: (A) Cmax = − 11.0 + 3.83·dose; (B) AUClast = − 24.2 + 42.9·dose. DMT N,N-dimethyltryptamine
See this image and copyright information in PMC

References

    1. Carhart-Harris RL, Bolstridge M, Day CMJ, Rucker J, Watts R, Erritzoe DE, et al. Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. Psychopharmacology. 2018;235(2):399–408. doi: 10.1007/s00213-017-4771-x. - DOI - PMC - PubMed
    1. Carhart-Harris RGB, Watts R, Baker-Jones M, Murphy-Beiner A, Murphy R, Martell J, Blemings A, Erritzoe D, Nutt DJ. Trial of psilocybin versus escitalopram for depression. N Engl J Med. 2021;384:1402–1411. doi: 10.1056/NEJMoa2032994. - DOI - PubMed
    1. Sanches RF, de Lima OF, Dos Santos RG, Macedo LR, Maia-de-Oliveira JP, Wichert-Ana L, et al. antidepressant effects of a single dose of ayahuasca in patients with recurrent depression: a SPECT study. J Clin Psychopharmacol. 2016;36(1):77–81. doi: 10.1097/JCP.0000000000000436. - DOI - PubMed
    1. Palhano-Fontes F, Barreto D, Onias H, Andrade KC, Novaes MM, Pessoa JA, et al. Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial. Psychol Med. 2019;49(4):655–663. doi: 10.1017/S0033291718001356. - DOI - PMC - PubMed
    1. Carhart-Harris RL, Muthukumaraswamy S, Roseman L, Kaelen M, Droog W, Murphy K, et al. Neural correlates of the LSD experience revealed by multimodal neuroimaging. Proc Natl Acad Sci U S A. 2016;113(17):4853–4858. doi: 10.1073/pnas.1518377113. - DOI - PMC - PubMed

Publication types

Associated data

LinkOut - more resources