Venlafaxine: Independent Evidence on Depression, GAD, Side Effects & Withdrawal

Table of contents

• Evidence summary
• What venlafaxine is
• How it works
• What it is prescribed for
• What works and what does not
• Benefits by claim
• Risks and all side effects
• All interactions
• Who should avoid venlafaxine
• Dosage and how to take it
• Follow the money: who makes it and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

The table below grades the main claims about venlafaxine. Independent sources are listed first where they exist.

Independent evidence and credibility scorecard

Tier 1 means the most independent source (regulators, government-funded or unfunded academic work with no drug-company money in the analysis). Tier 4 means manufacturer-run analyses. Credibility A–D combines independence with methodological quality.

What venlafaxine is

Venlafaxine is a serotonin and norepinephrine (noradrenaline) reuptake inhibitor, or SNRI (FDA label). It comes as immediate-release tablets taken twice a day and as prolonged-release ("slow-release", XL or XR) tablets and capsules taken once a day. It is available only on prescription (NHS).

Brand names and history. The originator brand is Effexor (Efexor in the UK), with the extended-release versions Effexor XR and Efexor XL. According to a US federal court's summary of the litigation record, the FDA approved Wyeth's New Drug Application for Effexor in December 1993. The venlafaxine patent had been assigned to Wyeth's predecessor, American Home Products (US District Court, D.N.J., 2014). Effexor XR (NDA 020699) was first approved on 20 October 1997, and the FDA now lists the application as held by Upjohn US (Federal Register, 19 December 2025). In the UK, Efexor XL was first authorised on 5 August 1997. The current marketing authorisation holder is Viatris Products Limited (Efexor XL SmPC).

Generic status. Venlafaxine is widely available as a generic. The UK electronic medicines compendium lists many generic immediate-release, prolonged-release and oral-solution products alongside the brand (example generic SmPC). In the US, the current Effexor XR label is issued by Viatris Specialty LLC (DailyMed).

Related drug. Venlafaxine's main active metabolite is O-desmethylvenlafaxine (ODV), which is sold separately as desvenlafaxine. The FDA label lists hypersensitivity to either drug as a contraindication (FDA label).

How it works

The FDA label says venlafaxine's mechanism in depression and anxiety "is unclear". It is thought to be related to boosting serotonin and norepinephrine activity in the central nervous system by blocking their reuptake (FDA label). Its effect on noradrenaline depends on dose. A Wyeth-authored analysis describes it as inhibiting serotonin reuptake and, at higher doses, noradrenaline reuptake (Thase et al., 2001). A Cochrane review calls it a serotonin reuptake inhibitor and a "weak" noradrenaline reuptake inhibitor (Gallagher et al., 2015). This dose dependence is the likely explanation for the blood pressure rises seen at higher doses, which an early pooled analysis attributed to "noradrenergic potentiation" (Thase, 1998).

Pharmacokinetics. The liver converts venlafaxine, mainly through the enzyme CYP2D6, into its active metabolite ODV. The apparent elimination half-life is about 5 ± 2 hours for venlafaxine and 11 ± 2 hours for ODV. Food does not affect absorption (FDA label). This short half-life is one reason missed doses and abrupt stopping can quickly lead to discontinuation symptoms. The UK SmPC notes that withdrawal symptoms have occasionally been reported after a missed dose (Efexor XL SmPC).

What it is prescribed for

A UK regulatory history worth knowing. Concerns about cardiotoxicity and overdose led UK regulators in 2004 to restrict venlafaxine to specialist initiation and to recommend baseline ECGs. After a further review in May 2006, the MHRA accepted that baseline ECGs were unnecessary for most patients. It concluded that venlafaxine was "an appropriate second-line antidepressant (after an SSRI)" that non-specialists could prescribe at doses under 300 mg per day. It also acknowledged data showing that venlafaxine is more likely than SSRIs to be prescribed to patients at risk of suicide (McAllister-Williams et al., Br J Gen Pract 2006).

What works and what does not

Benefits by claim

Depression: effective, but read the numbers carefully

The most independent and comprehensive estimate comes from the Cipriani 2018 network meta-analysis in The Lancet. It searched published and unpublished double-blind trials, included 522 trials with 116,477 participants, and was funded by the UK National Institute for Health Research and the Japan Society for the Promotion of Science, with "no role" for the funder in the study (Cipriani et al., 2018). Against placebo, venlafaxine's odds ratio for response was 1.78 (95% CrI 1.61–1.96). Only amitriptyline (2.13), mirtazapine (1.89) and duloxetine (1.85) had higher point estimates. Its odds ratio for dropping out for any reason was 1.04 (0.93–1.15), which is not significantly different from placebo (Cipriani 2018, figure 3).

These figures need context:

• Odds ratios are relative measures. The authors called the summary effect sizes "mostly modest". Differences between individual antidepressants were smaller when placebo-controlled trials were included than in head-to-head trials alone (Cipriani 2018).
• Head-to-head trials pull in opposite directions. In direct comparisons, venlafaxine was one of seven antidepressants that were more effective than others (ORs 1.19–1.96). It was also one of seven with the highest dropout rates (ORs 1.30–2.32) (Cipriani 2018).
• Certainty was often low. Using GRADE, the authors rated the quality of many comparisons as low or very low for amitriptyline, bupropion and venlafaxine (Cipriani 2018).
• A novelty effect was found. Across the dataset, a drug appeared more effective when it was the new, experimental drug in a trial than when it was the older comparator (1.18 times, 95% CrI 1.09–1.27). Adjusting for this reduced the differences between drugs (Cipriani 2018).
• Placebo response is large in antidepressant trials. The authors discuss how trial design, such as the chance of receiving placebo and how often patients are seen, affects placebo response rates (Cipriani 2018). An odds ratio of 1.78 describes the extra benefit over a placebo group that also improves substantially.

Is venlafaxine better than SSRIs? The manufacturer's evidence versus independent evidence

Venlafaxine was long promoted as potentially more effective than SSRIs. The main evidence for this came from the manufacturer's own data:

• A 2001 pooled analysis of eight randomised trials found remission rates of 45% on venlafaxine, 35% on SSRIs and 25% on placebo (OR 1.50 for remission, venlafaxine vs SSRIs) (Thase, Entsuah & Rudolph, BJP 2001). The journal page lists two co-authors at Wyeth-Ayerst Research and states that the lead author "is a paid consultant to Wyeth–Ayerst Laboratories, the employer of A.R.E. and R.L.R." (BJP article page).
• The larger COMPARE meta-analysis pooled 34 studies "sponsored by Wyeth Pharmaceuticals". It found a 5.9% difference in remission favouring venlafaxine, an NNT of 17. The difference was significant against fluoxetine but not individually against paroxetine, sertraline or citalopram, and more patients stopped venlafaxine because of adverse events (11% vs 9%). The authors themselves wrote that "the clinical significance of this modest advantage seems limited" (Nemeroff et al., Biol Psychiatry 2008).

The independent counterweight is the AHRQ-funded review by Gartlehner and colleagues. Covering 234 studies, it found "no clinically relevant differences in efficacy or effectiveness" among second-generation antidepressants and concluded that current evidence does not justify recommending one on efficacy grounds (Gartlehner et al., Ann Intern Med 2011). Pure City Research's reading is that any remission advantage over SSRIs as a class is small, rests largely on sponsor-selected trials, and is not enough on its own to justify choosing venlafaxine over an SSRI.

Preventing relapse and recurrence

In the Wyeth-sponsored PREVENT study, patients who had already responded to venlafaxine ER through acute treatment, continuation and a first maintenance year were randomised again. Over the second year, the cumulative probability of recurrence was 8.0% on venlafaxine ER (n = 43) vs 44.8% on placebo (n = 40). Over 24 months, the figures were 28.5% vs 47.3% (Keller et al., 2007; sponsor listed at ClinicalTrials.gov). This "enriched" design, which enrols only people who have already responded to the drug, tends to show large maintenance effects. When placebo patients relapse, some of that relapse may also reflect withdrawal effects or the underlying illness returning after the drug is stopped. This is a general limitation of such designs, not a finding of this trial. NICE advises taking antidepressants typically for at least 6 months, including after symptoms remit (NICE NG222).

Generalised anxiety disorder

The unfunded Slee 2019 network meta-analysis covered 89 trials and 25,441 patients. Venlafaxine reduced Hamilton Anxiety Scale scores by 2.69 points more than placebo (95% CrI −3.50 to −1.89), similar to escitalopram (−2.45) and pregabalin (−2.79) and a little below duloxetine (−3.13). All four had "relatively good acceptability" (Slee et al., Lancet 2019). Quetiapine had the largest effect but was poorly tolerated. On average, the difference from placebo is a few points on a clinician-rated scale, so the benefit is real but moderate. NICE notes that the full anxiolytic effect develops gradually, over 1 week or more (NICE CG113).

Panic disorder and social anxiety disorder

In the 2023 Cochrane network meta-analysis of panic disorder, venlafaxine was among the medicines with the strongest effect on response and was more effective than placebo for remission. The authors concluded that SSRIs, SNRIs (venlafaxine), tricyclics, MAOIs and benzodiazepines "may be effective, with little difference between classes". They also warned that all the studies had unclear or high risk of bias (Guaiana et al., 2023). For social anxiety disorder, Cochrane found venlafaxine reduced symptom severity. However, more people withdrew from treatment on venlafaxine than on placebo (RR 3.23), although absolute withdrawal rates were low (Williams et al., 2017). The FDA label notes that in social anxiety disorder "there was no evidence that higher doses confer any additional benefit" above 75 mg/day (FDA label).

Off-label uses

For hot flushes, a Mayo Clinic-led, NCI-supported randomised trial found median hot-flush scores fell by 27% on placebo, 37% on 37.5 mg, and 61% on both 75 mg and 150 mg over 4 weeks. The higher doses caused more dry mouth, decreased appetite, nausea and constipation (Loprinzi et al., Lancet 2000). For neuropathic pain, Cochrane found "little compelling evidence" to support its use (Gallagher et al., 2015).

Risks and all side effects

Common side effects

In placebo-controlled trials of up to 12 weeks (3,558 people on Effexor XR and 2,197 on placebo), the most common adverse reactions occurring at least twice as often as on placebo were (FDA label):

Overall, 12% of patients on Effexor XR stopped short-term trials because of an adverse event, compared with 4% on placebo. Nausea was the most common reason (4.3% vs 0.4%) (FDA label). The NHS lists headaches, feeling or being sick, dizziness or drowsiness, dry mouth, diarrhoea or constipation, sexual problems, insomnia and weight changes as common, and notes that most ease after a couple of weeks (NHS). The UK SmPC adds that dry mouth, reported in 10% of patients, may increase the risk of tooth decay (Efexor XL SmPC).

Serious and important risks

Withdrawal (discontinuation) symptoms

This is venlafaxine's most distinctive practical problem. The FDA label says that stopping or reducing the dose can cause new symptoms, and that these become more frequent at higher doses and after longer treatment. The listed symptoms include dizziness, "shock-like electrical sensations", nausea, anxiety, agitation, confusion, insomnia, nightmares, sweating, tremor, vertigo, headache and flu-like symptoms. There are postmarketing reports of "serious discontinuation symptoms which can be protracted and severe". Suicide, suicidal thoughts, aggression and violent behaviour have been observed during dose reduction, and some patients may need to taper "over a period of several months" (FDA label). The UK SmPC reports discontinuation adverse events in about 31% of venlafaxine-treated patients vs 17% on placebo in clinical trials. It notes that very rarely symptoms have followed a missed dose, and that raised blood pressure can occur on stopping (Efexor XL SmPC).

Independent estimates differ, partly because studies define and measure withdrawal differently:

• Henssler et al. 2024 (unfunded, 79 studies, 21,002 patients): after stopping any antidepressant, 31% had at least one discontinuation symptom, compared with 17% after stopping placebo. The placebo-adjusted incidence was about 15%, or one in six to seven people. Severe symptoms affected 2.8% vs 0.6% after placebo. Venlafaxine and desvenlafaxine were among the drugs associated with higher frequency, and with higher severity (Henssler et al., Lancet Psychiatry 2024).
• Davies & Read 2019: across 14 studies, withdrawal incidence ranged from 27% to 86%, with a weighted average of 56%. Many people had symptoms lasting more than two weeks (Davies & Read, Addict Behav 2019). This review pooled very different designs, and its authors list affiliations with withdrawal-advocacy bodies.
• Fava et al. 2018 (61 reports on SNRIs): withdrawal "appeared to be higher with venlafaxine". Symptoms usually began within days, lasted a few weeks even with gradual tapering, and sometimes appeared late or persisted longer (Fava et al., Psychother Psychosom 2018).

NICE's 2022 depression guideline tells clinicians that "paroxetine and venlafaxine, are more likely to be associated with withdrawal symptoms, so particular care is needed with them". It advises restarting the previous dose and then reducing more slowly if severe symptoms occur (NICE NG222).

Dependence

Venlafaxine is not a controlled substance. The FDA label reports no significant stimulant or depressant abuse liability in animal studies. It does cause physical dependence in the pharmacological sense, meaning the body adapts to the drug so that stopping it causes withdrawal (FDA label). This is different from addiction, which involves craving and compulsive use.

Toxicity in overdose

Venlafaxine sits between the SSRIs and the older tricyclic antidepressants for danger in overdose:

• UK mortality data (1993–1999) gave a fatal toxicity index of 13.2 deaths per million prescriptions (95% CI 9.2–18.5) for venlafaxine. The comparable figures were 1.6 for serotonergic drugs overall, 0.7–3.0 for individual SSRIs and 34.8 for tricyclics. The study declared no funding (Buckley & McManus, BMJ 2002).
• An NIHR-funded study of England and Wales (2000–2006) found case fatality rate ratios of 13.8 for tricyclics, 2.5 for venlafaxine, 1.9 for mirtazapine and 0.5 for SSRIs. The authors noted that venlafaxine "tends to be more often prescribed for, and taken in overdose by, people with longer-term psychiatric disorders and a history of self-harm" (Hawton et al., BJP 2010).
• In an Australian cohort of 538 antidepressant self-poisoning admissions, seizures occurred in 7 of 51 venlafaxine overdoses (14%), all involving at least 900 mg. The odds ratio for seizures compared with tricyclics was 4.4 (Whyte et al., QJM 2003).

Both the FDA label and the UK SmPC say that venlafaxine overdose "may be associated with an increased risk of fatal outcomes compared to that observed with SSRI antidepressant products, but lower than that for tricyclic antidepressants". They add that venlafaxine-treated patients have a higher pre-existing burden of suicide risk factors, so how much of the difference comes from the drug itself is "not clear". The SmPC notes that severe poisoning may occur in adults after about 3 grams. Both documents advise prescribing the smallest quantity consistent with good care (FDA label; Efexor XL SmPC). NHS guidance is to call 111 if you have taken more than your prescribed dose, and not to drive yourself to A&E (NHS).

All interactions

Who should avoid venlafaxine

• Contraindicated: people allergic to venlafaxine, desvenlafaxine or any ingredient, and anyone taking an MAOI or within the washout period (FDA label; SmPC).
• Needs specialist caution: the NHS says venlafaxine may not be suitable if you have diabetes, epilepsy, heart disease, glaucoma, a bleeding disorder (particularly gastrointestinal bleeding), or a personal or family history of mania (NHS). It has not been evaluated in people with a recent heart attack or unstable heart disease (SmPC).
• Uncontrolled high blood pressure: this must be controlled before starting (FDA label).
• High suicide risk: because of its toxicity in overdose, NICE asks prescribers to weigh "the risk of suicide and likelihood of toxicity in overdose (especially with venlafaxine)" (NICE CG113). Smaller prescription quantities are advised (SmPC).
• Children and adolescents: not recommended in the UK and not approved in the US. Paediatric trials showed no efficacy, along with weight loss, reduced growth and suicidal ideation (FDA label; Cipriani 2016).
• Pregnancy: the NHS says it can be used if needed, at the lowest effective dose, and you may be advised to give birth in hospital (NHS). The FDA label reports no identified drug-associated risk of major birth defects in published epidemiological data. It does note a possible increased risk of pre-eclampsia with use in mid to late pregnancy, a less than 2-fold increase in postpartum haemorrhage with use in the month before delivery, and complications in newborns exposed late in the third trimester, some needing respiratory support or tube feeding (FDA label). Stopping also carries a risk: the label cites a study in which women who discontinued antidepressants during pregnancy were more likely to relapse than those who continued (FDA label). Do not stop without advice.
• Breastfeeding: venlafaxine and ODV pass into breast milk. Irritability, crying and abnormal sleep have been reported in breastfed infants (SmPC). The NHS says it is sometimes used if the benefits outweigh the risks (NHS).
• Older adults: no dose change is needed for age alone, but caution is advised because of possible kidney impairment and a greater risk of hyponatraemia. The lowest effective dose should be used (SmPC; FDA label). Note: we could not access the full 2023 AGS Beers Criteria tables during this review, so no Beers-specific wording is given here.
• Liver impairment: the FDA label advises reducing the dose by 50% in mild to moderate impairment, and by 50% or more in severe impairment or cirrhosis (FDA label).
• Kidney impairment: the FDA label advises reducing the dose by 25–50% in mild to moderate impairment, and by 50% or more in severe impairment or dialysis. The UK SmPC advises a 50% reduction when GFR is below 30 ml/min or with haemodialysis (FDA label; SmPC).

Dosage and how to take it

Sources: Efexor XL SmPC; FDA Effexor XR label. For depression, UK immediate-release tablets start at 75 mg/day in two divided doses with food, with a maximum of 375 mg/day (venlafaxine 75 mg tablets SmPC). Hepatic and renal adjustments are listed under Who should avoid. Remember that the MHRA's 2006 review allowed non-specialists to prescribe venlafaxine at doses under 300 mg/day (BJGP 2006), and that blood pressure effects rise with dose.

How to take it

• Take slow-release forms once a day, and other forms twice a day, ideally at the same times each day. Swallow tablets and capsules whole with water and take them with food (NHS). Do not crush or chew prolonged-release capsules (SmPC).
• Missed dose: take it when you remember unless your next dose is nearly due. Never double up (NHS).
• Checks: blood pressure before starting and regularly during treatment (FDA label). An early review is advised for people aged 18–25 or anyone with suicide risk (NICE NG222).

How long before it works

For depression, NICE says the benefits of antidepressant medication "should be felt within 4 weeks". Treatment is typically continued for at least 6 months, including after symptoms remit (NICE NG222). For GAD, NICE describes the full anxiolytic effect developing gradually, over 1 week or more (NICE CG113). The NHS notes that the dose may be raised after 2 to 3 weeks (NHS).

How to stop safely

Do not stop suddenly. The NHS says your doctor "will gradually reduce your dose over several weeks or months" (NHS). The UK SmPC advises tapering over at least 1–2 weeks, adding that "in some patients, discontinuation may need to occur very gradually over periods of months or longer" (SmPC). NICE advises taking into account the medicine's half-life, since antidepressants with a short half-life need slower tapering, and how long it has been taken. It recommends reducing step by step, each time to a proportion of the previous dose (for example 50%), using smaller reductions (for example 25%) as the dose gets lower, and allowing 1 to 2 weeks to judge each reduction. If severe symptoms occur, NICE advises returning to the previous dose and then reducing more slowly (NICE NG222). Work out the plan with your prescriber, as the right pace varies from person to person.

Follow the money: who makes it and who funded the evidence

Originator and current owners

• Originator: Wyeth (US), formerly American Home Products. The venlafaxine compound patent was assigned to American Home Products, and the FDA approved Wyeth's Effexor application in December 1993 (US District Court record).
• Revenue. Effexor was Wyeth's largest product line. It generated net revenue of $3,722.1 million in 2006, $3,793.9 million in 2007 and $3,927.9 million in 2008, about 17–18% of the company's total net revenue (Wyeth 2008 Financial Report, SEC filing).
• Pfizer (US). Pfizer completed its acquisition of Wyeth in October 2009 (Pfizer press release).
• Viatris (US-headquartered). In November 2020, Pfizer's off-patent Upjohn business was combined with Mylan to form Viatris Inc. (SEC Form 8-K, 16 November 2020). Viatris now issues the US Effexor XR label, and Viatris Products Limited holds the UK Efexor XL authorisation. The FDA lists NDA 020699 as held by Upjohn US (DailyMed; SmPC; Federal Register).
• Generics. Many generic manufacturers now supply venlafaxine in the UK and US (example UK generic SmPC). This means no single company today has a strong commercial stake in the molecule. The strongest financial interests existed in the Wyeth era, which is when most of the pivotal and comparative trials were run.

Who funded the evidence

• Pivotal licensing trials: run by the manufacturer. The efficacy and harm data in the FDA and UK labels come from Wyeth's premarketing programme and were reviewed by regulators (FDA label).
• "Better than SSRIs" analyses: based only on Wyeth-sponsored trials. The 2001 paper was co-written by Wyeth employees and a Wyeth-paid consultant (Thase 2001; COMPARE 2008).
• Long-term relapse prevention (PREVENT): Wyeth-sponsored (ClinicalTrials.gov).
• Independent syntheses: Cipriani 2018 (NIHR and JSPS), Slee 2019 (unfunded), Gartlehner 2011 (AHRQ), Henssler 2024 (unfunded), Hawton 2010 (NIHR) and Buckley 2002 (unfunded). These independent analyses confirm that venlafaxine works in depression and GAD. They do not support a meaningful advantage over SSRIs, and they highlight its withdrawal and overdose risks. Cipriani and colleagues found that industry funding was not associated with substantial differences in response or dropout, but warned that non-industry trials "were few and many trials did not report or disclose any funding" (Cipriani 2018).

Documented legal and competition events

• Generic-entry settlement. Wyeth sued Teva in 2003 over Teva's generic Effexor XR application and settled in December 2005. Under the settlement, Teva was licensed to launch generic Effexor XR from 1 July 2010, subject to earlier-launch conditions (Wyeth 2008 Financial Report). The US Federal Trade Commission later filed an amicus brief (2015) describing allegations that Wyeth "agreed not to launch an 'authorized generic version'" to induce Teva to abandon its patent challenge. The FTC argued that submitting the deal to the FTC did not protect the companies from antitrust liability (FTC, 2015). These are allegations in private antitrust litigation, not findings against the companies.
• Product-liability suits. Wyeth's 2008 filing reports lawsuits alleging that Effexor caused suicide or hostility. In one, a jury returned a verdict for the company in 2007, which an appeals court affirmed in 2009 (Wyeth 2008 Financial Report). The suicidality risk itself is covered by the class-wide boxed warning described above.

Related research

• Stress, anxiety and depression: prevention and management guide
• Supplements for stress, anxiety and depression: the evidence
• St John's wort: do not combine with venlafaxine
• Saffron for depression
• Ashwagandha: evidence and safety
• L-theanine
• Magnesium
• Sleep prevention guide (insomnia is a common side effect)
• Sleep supplements evidence
• Melatonin
• Sibling medicine reviews: sertraline, escitalopram, duloxetine, mirtazapine, pregabalin

Frequently asked questions

Sources and funding notes

• NHS, Venlafaxine medicine page: UK government health service. Last reviewed 6 July 2026.
• Effexor XR prescribing information (DailyMed / FDA): manufacturer label (Viatris Specialty LLC), approved by the US FDA. Efficacy data come from manufacturer trials.
• Efexor XL 150 mg SmPC (emc): manufacturer (Viatris Products Ltd) product information, approved by the UK regulator.
• Venlafaxine 75 mg tablets SmPC (emc): generic manufacturer product information, regulator-approved.
• NICE NG222, Depression in adults (2022): UK government-funded guideline body.
• NICE CG113, Generalised anxiety disorder and panic disorder: UK government-funded. Some recommendations date from 2004–2011, amended 2020.
• NICE CG159, Social anxiety disorder (2013): UK government-funded.
• Cipriani et al., Lancet 2018 (full text): funded by the NIHR Oxford Health BRC (UK) and JSPS (Japan), with no funder role. Some authors declared pharma lecture or consulting fees.
• Slee et al., Lancet 2019: University College London. "No funding was received for this research."
• Guaiana et al., Cochrane 2023 (panic disorder NMA): multinational academic authors (Canada, UK, Italy, Japan). Several declared pharma lecture or research fees.
• Williams et al., Cochrane 2017 (social anxiety pharmacotherapy): University of Cape Town (South Africa). One author declared industry grants or honoraria.
• Gartlehner et al., Ann Intern Med 2011: primary funding from the Agency for Healthcare Research and Quality (US government).
• Thase, Entsuah & Rudolph, Br J Psychiatry 2001 (journal page): Wyeth-Ayerst trials, two Wyeth employee co-authors and a Wyeth-paid consultant lead author (US).
• Nemeroff et al., Biol Psychiatry 2008 (COMPARE): meta-analysis limited to research sponsored by Wyeth Pharmaceuticals (US). Author funding not stated in the abstract.
• Keller et al., J Clin Psychiatry 2007 (PREVENT): Wyeth-sponsored (NCT00046020) (US).
• Thase, J Clin Psychiatry 1998 (blood pressure): University of Pittsburgh. NIMH grant listed. Pooled controlled-trial data (the abstract does not state who supplied them).
• Henssler et al., Lancet Psychiatry 2024: University of Cologne and Charité Berlin (Germany). No funding and no competing interests.
• Davies & Read, Addict Behav 2019: Universities of Roehampton and East London (UK). Authors list affiliations with the All-Party Parliamentary Group for Prescribed Drug Dependence and the International Institute for Psychiatric Drug Withdrawal. No commercial funding stated.
• Fava et al., Psychother Psychosom 2018: University of Bologna (Italy). No funding stated in the abstract.
• Buckley & McManus, BMJ 2002: Australian clinical toxicologists using UK mortality data. Funding "None".
• Hawton et al., Br J Psychiatry 2010: NIHR Programme Grant (UK). One author sat on an MHRA advisory group.
• Whyte, Dawson & Buckley, QJM 2003: University of Newcastle (Australia) toxicology cohort. Funding not stated in the abstract.
• Cipriani et al., Lancet 2016 (children and adolescents): funded by the National Basic Research Program of China (973 Program).
• Gallagher et al., Cochrane 2015 (neuropathic pain): University College Dublin (Ireland). Health Research Board Cochrane Fellowship.
• Loprinzi et al., Lancet 2000 (hot flushes): Mayo Clinic (US). US National Cancer Institute grants listed.
• McAllister-Williams et al., Br J Gen Pract 2006 (letter on the MHRA venlafaxine review): UK clinicians' correspondence. Funding not stated.
• Federal Register, 19 December 2025 (FDA determination on Effexor XR 100 mg): US government.
• In re Effexor XR Antitrust Litigation, D.N.J. memorandum (2014): US federal court record summarising plaintiffs' allegations and background.
• US Federal Trade Commission, amicus brief press release (2015): US government competition regulator.
• Wyeth 2008 Financial Report (SEC 10-K exhibit): company filing, used for revenue and litigation facts.
• Pfizer, "Pfizer Completes Acquisition of Wyeth" (2009): company press release.
• Mylan II B.V., SEC Form 8-K (16 November 2020): company filing on the formation of Viatris.

Last reviewed: 26 September 2026. Educational information from Pure City Research, not medical advice. Medicine decisions belong with a qualified prescriber.