Lorazepam Stats & Data

Measured binding and functional data for lorazepam, curated by the IUPHAR/BPS Guide to PHARMACOLOGY. Each row cites the paper it came from. Lower concentrations mean tighter binding — a value in the sub-nanomolar range indicates a very potent interaction.

Reading this. pKi, pEC50 and pIC50 are negative log molar values, so a higher number means a tighter interaction; the concentration column converts them for you. Values from non-human species are laboratory measurements and do not translate directly to human effect. Receptor affinity is not a dose — it describes what a molecule binds, not how much of it is safe to take.

Receptor data from the IUPHAR/BPS Guide to PHARMACOLOGY (v2026.2), licensed CC BY-SA 4.0. Matched to this substance by InChIKey.

Lorazepam was initially patented in 1963 and is considered one of the "classical" benzodiazepines alongside diazepam, clonazepam, oxazepam, nitrazepam, flurazepam, bromazepam, and clorazepate. The compound was developed by D.J. Richards, who served as president of research at Wyeth Pharmaceuticals. The drug was introduced to the United States market in 1977 under the brand names Ativan and Temesta, with subsequent marketing under additional trade names in other regions. Wyeth's original patent on the compound has since expired. Lorazepam has achieved significant standing in modern pharmacology, being included on the World Health Organization's List of Essential Medicines. The compound is now available as a generic medication in many countries. As of 2023, it ranked as the 100th most commonly prescribed medication in the United States, with over six million prescriptions written annually. Non-medical use of lorazepam has been documented as a notable public health concern. A 2006 nationwide study by the Substance Abuse and Mental Health Services Administration examining pharmaceutical-related emergency department visits found that sedative-hypnotics represent the pharmaceutical category most frequently used outside of prescribed medical purposes in the United States, accounting for 35% of drug-related emergency department visits. Within this category, benzodiazepines constitute the most commonly encountered class, with lorazepam specifically ranking as the third-most-common benzodiazepine involved in non-prescription emergency department presentations.

Forked from Subjective Effect Documentation by Josie Kins, September 2015. Via dose.wiki (CC0).

Lorazepam likely has a low toxicity relative to dose. However, it is potentially lethal when mixed with depressants like alcohol or opioids. It is strongly recommended that one use harm reduction practices when using this substance.

Effects aggregated from 49 experience reports (39 single-substance Erowid + 10 Bluelight)

Each bar is the share of reports mentioning the effect; its whisker, and the band on the rows below, is the 95% interval: where the share could plausibly be with other reports of the same kind.

Rows resting on fewer than 20 reports show a count (“3 of 7”) instead of a bar. Why 20?

Also reported in combinations. In the 57 Lorazepam reports where another drug was taken too, 19 (33.3%) mention hospital, emergency services or an overdose, 3 (5.3%) a seizure and 2 (3.5%) psychosis. In the 39 single-substance reports: 17.9%, 2.6% and 2.6%. These are not in the figures above: they cannot be put down to Lorazepam alone, and a mention is not always something that happened to the writer.

How effect frequency changes across dose levels. Whiskers, and the numbers' hover text, give each figure's 95% interval.

Not drawn, too few reports (a dose tier needs 20): Oral Common (n=10), Oral Heavy (n=12). Why 20?

Dose distribution from experience reports, one dose per report (the first listed). Doses above Q3 + 3×IQR, far above what people typically take, are left out of the median and range and listed under each route: most are real heavy doses or overdoses, not mistakes.

From 172 of 189 recorded dose entries: those that state a weight (mg, g or µg), in routes with at least five of them. Values above Q3 + 3×IQR, far above what people typically take, are left out; they can include real heavy doses and overdoses, not only mistakes.

Most co-occurring substances, as a share of all 96 reports filed under Lorazepam; whiskers are 95% intervals

Most common forms and preparations, as a share of the 75 reports that give one; whiskers are 95% intervals

Dose per kg of body weight, one dose per report (the first listed), from reports giving a weight of 30–250 kg. Doses above Q3 + 3×IQR, far above what people typically take, are left out of the median and range and listed under each route.

Redosing behavior across 90 reports