the public record, side by side

Klonopin (clonazepam) vs Valium (diazepam)

Klonopin and Valium, compared on what the public record actually supports: side effects by rate from each FDA label, what the largest trial comparison found, who takes each one, who pays, what the labels warn, and what the litigation record holds. Sources on every number.

the short answer

  • is Klonopin or Valium more effective? there is no head-to-head trial record in our library that settles this pair, and we do not fill the gap with a guess. what can be compared is below: each label's own side-effect table, who takes each drug, who pays, and the legal record.
  • which has fewer side effects? the labels say their trials “cannot be directly compared”, because each drug was tested in different people under different rules. what each label prints: Klonopin (clonazepam): 17% stopped for an adverse reaction vs 9% on placebo (Klonopin label, SPL version 6, effective 2025-12-01). Valium (diazepam): The ADVERSE REACTIONS section of the current Valium label contains no table, no incidence percentages, no Ns, and no placebo comparison of any kind — zero numbers appear anywhere in the section. There is no clinical-trials adverse-event dataset on the label at all; CLINICAL PHARMACOLOGY is pharmacokinetics only, with no efficacy-trial description. Also absent: any discontinuation-due-to-adverse-reaction rate and the "cannot be directly compared" preamble (that boilerplate belongs to labels that print trial rates; Valium prints none).
  • which should i take? not a question this page answers. the odds ratios are averages across thousands of strangers; your history, other medications and what you can live with are not in them. the questions for your prescriber below are built from what is on this page.

What this page will not do is rank them. For most same-class pairs, head-to-head efficacy differences are smaller than the rankings look — the largest network meta-analysis ever run (21 antidepressants, 522 trials) found every drug beat placebo and the gaps between drugs mostly modest and uncertain. Which one fits you turns on your history, your other medications, and side-effect trade-offs — a prescriber conversation. This page arms that conversation; here are the questions worth taking into it →

side effects by rate: what each label prints, not a head-to-head trial

the labels' own warning, first: “The prescriber should be aware that the figures in Table 3 cannot be used to predict the incidence of side effects in the course of usual medical practice where patient characteristics and other factors differ from those that prevailed in the clinical trials. Similarly, the cited frequencies cannot be compared with figures obtained from other clinical investigations involving different treatments, uses and investigators. The cited figures, however, do provide the prescribing physician with some basis for estimating the relative contribution of drug and nondrug factors to the side effect incidence in the population studied.” the two columns below come from different trials, in different people, under different inclusion rules. read each against its own placebo column, not against the other drug.

the two labels list fewer than three reactions under the same name, so there is no side-by-side table here; each label's full table is on the tool page linked below.

  • Klonopin (clonazepam): 17% stopped for an adverse reaction vs 9% on placebo (Klonopin label, SPL version 6, effective 2025-12-01).
  • Valium (diazepam): The ADVERSE REACTIONS section of the current Valium label contains no table, no incidence percentages, no Ns, and no placebo comparison of any kind — zero numbers appear anywhere in the section. There is no clinical-trials adverse-event dataset on the label at all; CLINICAL PHARMACOLOGY is pharmacokinetics only, with no efficacy-trial description. Also absent: any discontinuation-due-to-adverse-reaction rate and the "cannot be directly compared" preamble (that boilerplate belongs to labels that print trial rates; Valium prints none).
what makes each table, in the labels' words
  • Klonopin (clonazepam), SPL version 6, effective 2025-12-01, ADVERSE REACTIONS (old-format label; panic-disorder subsection), tablets, 0.5 mg / 1 mg / 2 mg (Schedule IV controlled substance). inclusion rule: “Table 3 enumerates the incidence, rounded to the nearest percent, of treatment-emergent adverse events that occurred during acute therapy of panic disorder from a pool of two 6- to 9-week trials. Events reported in 1% or more of patients treated with Klonopin (doses ranging from 0.5 to 4 mg/day) and for which the incidence was greater than that in placebo-treated patients are included.” trials: “The panic-disorder data come from two double-blind, placebo-controlled studies of adult outpatients with a primary diagnosis of panic disorder (DSM-IIIR) with or without agoraphobia: Study 1, a 9-week fixed-dose study (Klonopin 0.5, 1, 2, 3 or 4 mg/day or placebo), and Study 2, a 6-week flexible-dose study (0.5 to 4 mg/day; mean dose during optimal dosing 2.3 mg/day). Label methodology note: "Adverse events during exposure to Klonopin were obtained by spontaneous report and recorded by clinical investigators using terminology of their own choosing… CIGY dictionary terminology has been used to classify reported adverse events… An event was considered treatment-emergent if it occurred for the first time or worsened while receiving therapy following baseline evaluation."” DailyMed
  • Valium (diazepam), SPL version 11, effective 2026-08-11, ADVERSE REACTIONS (old-format label), tablets (Schedule IV controlled substance). DailyMed

every row above was transcribed from the current FDA label on 2026-09-08; the full tables, including the reactions only one label lists, are on side-effect rates, drug vs placebo. the sexual side-effect rows carry each label's own underreporting caveat on the SSRI sexual side effects page.

clonazepam (Klonopin)

benzodiazepine

FDA approval
1975 — for seizure disorders; the panic indication came in the 1990s · full approval journey →
Who takes it (US, 2024)
2,154,594 patients · 11,861,003 prescriptions (AHRQ MEPS)2014 → 2024: 21,021,489 → 11,861,003 prescriptions, down 44%Correction (29 September 2026): An earlier version of this section took its numbers from ClinCalc DrugStats, a third-party site that republishes this survey; we now compute them from AHRQ’s public-use files ourselves.
Who pays (2024)
Medicare: 8,856,358 claims · 1,315,917 beneficiariesMedicaid: ≥3,836,777 prescriptionsCommercial claims: not published in any public dataset — a real absence, not a zero.
Boxed warning
Yes — on the current FDA label. read it in context →
Adverse-event reports (FAERS)
Caveat first: FAERS counts unverified REPORTS, not patients or rates — no denominator, and attention inflates reporting. Never compare these counts head-to-head; a longer-marketed, more-prescribed drug accumulates more reports by exposure alone. how to read FAERS →159,283 all-time reports; most-reported terms: drug ineffective, fatigue, nausea
Legal & safety record
no dedicated record page yet; the journey page carries label history

diazepam (Valium)

benzodiazepine

FDA approval
1963 · full approval journey →
Who takes it (US, 2024)
1,047,987 patients · 3,346,944 prescriptions (AHRQ MEPS)2014 → 2024: 9,134,522 → 3,346,944 prescriptions, down 63%Correction (29 September 2026): An earlier version of this section took its numbers from ClinCalc DrugStats, a third-party site that republishes this survey; we now compute them from AHRQ’s public-use files ourselves.
Who pays (2024)
Medicare: 3,011,861 claims · 939,381 beneficiariesMedicaid: ≥1,304,365 prescriptionsCommercial claims: not published in any public dataset — a real absence, not a zero.
Boxed warning
Yes — on the current FDA label. read it in context →
Adverse-event reports (FAERS)
Caveat first: FAERS counts unverified REPORTS, not patients or rates — no denominator, and attention inflates reporting. Never compare these counts head-to-head; a longer-marketed, more-prescribed drug accumulates more reports by exposure alone. how to read FAERS →121,002 all-time reports; most-reported terms: toxicity to various agents, drug ineffective, drug abuse
Legal & safety record
no dedicated record page yet; the journey page carries label history

questions for your prescriber, built from this page

this page does not tell you to start, stop or switch anything. it arms the conversation where that decision belongs. take these in:

  1. which of Klonopin and Valium did you have in mind first, and what in my history points that way?
  2. the trials put these two close together on average. what, for me specifically, breaks the tie: another medication i take, a side effect i can't live with, sleep, weight, sexual function?
  3. the label lists these reactions above placebo for the one you're suggesting. which of them should i expect in the first weeks, and which would make you want to hear from me the same day?
  4. how long were the approval trials, and what do we know past that point?
  5. how will we judge whether it is working, by when, and what is the plan if it isn't?
  6. if i ever want to come off it, how is that done, and over how long?
  7. is there a cheaper generic or a formulation that changes the dosing, and does my insurance prefer one of these two?

the longer checklist, for any antidepressant, is questions to ask before starting antidepressants. if you are already on one and it feels like it stopped working, that has its own page.

What the warnings mean, drug by drug

Each explainer reads one drug's current FDA label and the studies in our library, in both directions: the boxed warnings with the label's own numbers, the trials behind the approval and how long they ran, side effects by rate, and the research since.

Questions people search

Is Klonopin or Valium better?

No honest page can answer that in one line. Head-to-head differences between comparable psychiatric medications are usually smaller than rankings suggest, and which fits you depends on your history, other medications, and side-effect trade-offs, a prescriber conversation. What can be compared is the public record (usage, payers, label warnings, approval history, litigation), which is what this page does, with sources.

Is Klonopin the same as clonazepam, and Valium the same as diazepam?

Klonopin is a brand name for clonazepam. Valium is a brand name for diazepam. clonazepam is a benzodiazepine; diazepam is a benzodiazepine. This page uses the generic names because the federal datasets do.

Which has fewer side effects, Klonopin or Valium?

The two FDA labels cannot be compared head to head, in their own words, because each drug's trials ran in different people under different rules. What each label prints: Klonopin (clonazepam): 17% stopped for an adverse reaction vs 9% on placebo (Klonopin label, SPL version 6, effective 2025-12-01). Valium (diazepam): The ADVERSE REACTIONS section of the current Valium label contains no table, no incidence percentages, no Ns, and no placebo comparison of any kind — zero numbers appear anywhere in the section. There is no clinical-trials adverse-event dataset on the label at all; CLINICAL PHARMACOLOGY is pharmacokinetics only, with no efficacy-trial description. Also absent: any discontinuation-due-to-adverse-reaction rate and the "cannot be directly compared" preamble (that boilerplate belongs to labels that print trial rates; Valium prints none). The page shows the reactions both labels list, each against its own placebo column.

Which is prescribed more, Klonopin or Valium?

The page shows federal survey estimates we compute from AHRQ’s Medical Expenditure Panel Survey public-use files for both clonazepam and diazepam: patients and prescriptions in the latest reliable year, and the yearly series from 2014 where AHRQ’s reliability rule allows it, with a direction stated only when the change is larger than the survey’s margin of error. Prescription volume reflects habits, prices, and marketing as much as evidence, so it is context, not a verdict.

Where these numbers come from

  • Patients and prescriptions: computed by us from AHRQ's public-use Medical Expenditure Panel Survey Prescribed Medicines files, 2014 (HC-168A) to 2024 (HC-254A), with AHRQ's reliability rule (a year with fewer than 60 respondents or a relative standard error over 50% is not shown) — counts of people filling prescriptions, not outcomes. A direction is stated only when the change is larger than the survey's margin of error. Until 29 September 2026 these came from ClinCalc DrugStats, a third-party site; see the correction under each drug where a figure changed.
  • Medicare/Medicaid: CMS public datasets; commercial insurance publishes no per-drug series, so it renders as an absence, never a synthesized number.
  • Label facts: the drugs' current FDA labels via DailyMed — quoted in context on each drug's approval-journey page.
  • FAERS: openFDA — reports, never rates; the caveat travels above every count.
  • Litigation: court records and regulator documents only, on the linked record pages; settled is never adjudicated.

Explore both drugs in depth: /m/clonazepam · /m/diazepam · or the whole library →