Antipsychotics and Metabolic Health: What Monitoring Should Look Like

Anyone starting an antipsychotic should have weight, blood pressure, blood sugar and cholesterol measured before the first dose and checked again on a schedule: weight frequently in the first three months, then blood sugar, lipids and blood pressure at about 12 weeks, and at least yearly after that. FDA labels for antipsychotics such as olanzapine warn that this class of medicine has been associated with high blood sugar, unfavorable cholesterol changes and weight gain.

The risk is not the same for every drug. A large 2020 analysis found olanzapine and clozapine had the worst metabolic profiles and aripiprazole, brexpiprazole, cariprazine, lurasidone and ziprasidone the most benign. Good monitoring catches changes early, while there is still time to adjust the medication, add treatment or change course.

Why antipsychotics need metabolic monitoring

Second-generation antipsychotics are used for schizophrenia, bipolar disorder and, for some drugs, depression; oral olanzapine, for example, is approved for schizophrenia and bipolar I disorder, and in combination with fluoxetine for treatment-resistant depression. Their labels describe metabolic changes including hyperglycemia, dyslipidemia and weight gain, and in some cases extreme high blood sugar has been reported. The olanzapine label, for example, calls for fasting blood glucose testing and fasting lipids at the beginning of and periodically during treatment, and regular weight monitoring.

Metabolic change can begin early. In a 2020 network meta-analysis of 100 short-term trials with 25,952 patients, mean weight gain over a median of 6 weeks ranged from no meaningful change with haloperidol to about 3 kg with clozapine compared with placebo. The same analysis found that higher starting weight and male sex predicted larger increases in glucose, and that symptom improvement tended to go along with weight gain, which is one reason the decision is a balance rather than a simple choice of the "lightest" drug.

The ADA/APA monitoring schedule

In 2004, the American Diabetes Association, the American Psychiatric Association, the American Association of Clinical Endocrinologists and the North American Association for the Study of Obesity published a joint consensus statement on antipsychotic drugs, obesity and diabetes. Its monitoring schedule is widely reproduced, for example by insurers and in clinical journals.

The schedule above is as reproduced in a US behavioral health insurer's monitoring guide citing the 2004 consensus; a 2010 journal reproduction shows the same intervals for the measures above, also lists waist circumference, and notes that assessment frequency should be based on individual status. The "every 5 years" lipid interval is therefore a minimum; monitoring can be more frequent with higher-risk drugs or abnormal results.

The NICE version

The UK's NICE bipolar disorder guideline sets a similar but more front-loaded schedule. Before an antipsychotic, it calls for weight or BMI, pulse, blood pressure, fasting glucose or HbA1c, and a lipid profile. During treatment, it recommends pulse and blood pressure after each dose change, weight or BMI weekly for the first 6 weeks and then at 12 weeks, and fasting glucose or HbA1c and lipids at 12 weeks, followed by a physical health check at least once a year. NICE also recommends an ECG before starting in some situations, such as a cardiovascular risk found on examination or a family history of cardiovascular disease.

Either schedule is reasonable. What matters is that someone is actually doing it and that the results reach the prescriber. If your primary care doctor orders your blood work, ask them to send results to your psychiatrist, and vice versa; how your psychiatrist and primary care doctor should work together explains how.

How the antipsychotics compare on metabolic risk

The 2020 network meta-analysis by Pillinger and colleagues ranked 18 antipsychotics on short-term changes in weight, BMI, cholesterol, triglycerides and glucose. Its key findings:

The authors stressed that the choice should still be individual, weighing symptoms, history and preferences. Trials in the analysis lasted a median of 6 weeks, so they say little about long-term differences.

Newer options

• Olanzapine with samidorphan (Lybalvi) is FDA-approved for schizophrenia and bipolar I disorder in adults. In a 24-week trial it produced less weight gain than olanzapine alone (an average 4.2% versus 6.6% increase in body weight), but people still gained weight, and the label says the effect of switching from long-term olanzapine is unknown. Its label still asks for monitoring of glucose, lipids and weight.
• Xanomeline and trospium (Cobenfy) is FDA-approved for schizophrenia in adults; its label attributes its effect to activity at muscarinic receptors in the brain. Its label's warnings do not include the metabolic-changes warning found on other antipsychotic labels; they focus on urinary retention, liver and biliary issues, slowed gut movement and increased heart rate. It is newer, so long-term experience is more limited.
• Clozapine is FDA-approved for severely ill people with schizophrenia who have not responded adequately to standard antipsychotic treatment. The FDA removed the clozapine REMS program effective 13 June 2025, but prescribers should still monitor the absolute neutrophil count (ANC), a white blood cell measure, on the schedule in the prescribing information. Clozapine also needs the same metabolic monitoring as any high-risk antipsychotic.

For how these medicines compare on effectiveness and other side effects, see schizophrenia medications compared and bipolar disorder medications compared.

If weight, glucose or cholesterol start to rise

The response depends on how large the change is, how well the medication is working, and what alternatives exist. Options a prescriber may discuss include:

1. Lifestyle support: nutrition counseling, physical activity and sleep, ideally started early rather than after significant weight gain.
2. Switching to an antipsychotic with a lower metabolic burden, when symptoms allow and the risk of relapse during a switch is acceptable.
3. Adding a medicine to limit weight gain or improve glucose, such as metformin.
4. Treating the specific problem directly, for example with cholesterol or blood pressure medication, often through primary care.

The order matters less than the timing. A small, early rise in weight or glucose gives the most room to act, because a switch can be planned calmly and lifestyle changes have a smaller gap to close. Waiting until a person has gained a large amount of weight, or developed diabetes, narrows the choices. If the current medication is working well for psychosis or mood, your prescriber may prefer to keep it and address the metabolic side effect directly rather than risk a relapse.

What the evidence says about metformin and other add-on medicines

Metformin is FDA-approved, with diet and exercise, to improve blood sugar control in type 2 diabetes; using it to prevent or reduce antipsychotic-related weight gain is off-label. A 2022 Cochrane review found low-certainty evidence that metformin may help prevent weight gain in people with schizophrenia taking antipsychotics, with an average difference of about 4 kg compared with placebo or usual care. The reviewers noted that the studies were small and short.

A 2026 network meta-analysis in JAMA Psychiatry of 95 trials of medicines for weight reduction in people with schizophrenia on antipsychotics found that semaglutide, liraglutide, topiramate, metformin and exenatide were associated with the largest reductions in weight, with moderate-certainty evidence, and that clinically meaningful weight change of 5% or more was seen with semaglutide and metformin. These uses are also off-label for this purpose, and each medicine has its own side effects and contraindications. The practice has written about GLP-1 medicines in psychiatry in GLP-1 medications in psychiatry.

A sample first-year monitoring calendar

Putting the schedules on a calendar makes them easier to follow. The example below combines the ADA/APA grid and the NICE recommendations for someone starting a new antipsychotic; your prescriber may add tests or check more often.

Common gaps, and how to close them

Monitoring schedules are simple on paper but easy to miss in practice. These are the gaps people most often run into:

• No baseline. If weight and labs were never measured before the first dose, later changes are hard to interpret. If you have already started, ask for a set of measurements now so there is a reference point.
• Split responsibility. A psychiatrist prescribes, a primary care doctor orders annual labs, and nobody connects the two. Decide at the start who orders and who reviews.
• Telehealth-only care. Video visits do not include a scale or a blood pressure cuff. A home scale and a validated upper-arm monitor, plus a lab near home, can fill that gap.
• Medication added later. When an antipsychotic is added to an antidepressant or another mood stabilizer, the baseline and follow-up schedule applies to the new medicine too.
• Results without action. A rising glucose or triglyceride level that is noted but not discussed is a missed opportunity. Ask at each visit whether anything in your numbers should change the plan.

None of these gaps requires new technology to fix. A shared list of dates and results, kept by you or in a patient portal, solves most of them.

What you can do between visits

• Weigh yourself at home once a week at the same time of day, and note the number. Early, steady gain is easier to address than a large change found months later.
• Book fasting blood work for the morning, and ask whether you should take your morning medicines before or after the draw.
• Watch for symptoms of high blood sugar, such as unusual thirst, frequent urination, increased hunger or weakness, and report them promptly.
• Keep copies of your results, or ask for portal access, so you can see trends.
• Bring your weight log and any questions to each visit. Ongoing medication management describes what these visits usually cover.

Do not stop an antipsychotic on your own because of weight gain or a lab result. NICE advises that an antipsychotic be reduced gradually, over at least 4 weeks, to lower the risk of relapse. Raise the concern with your prescriber; there are usually several options. If you are thinking about suicide or are in crisis, call or text 988 (the 988 Suicide & Crisis Lifeline) or go to the nearest emergency room.

Questions to ask your prescriber

If you are also taking lithium, its separate monitoring is covered in lithium monitoring: what to expect. For families dealing with a first episode, first episode of psychosis: what to do first explains early steps.

How the practice approaches it

The practice's ongoing care includes psychiatric evaluation and medication management, lab testing, and nutrition and lifestyle psychiatry. It has written more about this overlap in psychiatric medications for patients with metabolic concerns and labs to ask for: a psychiatrist's metabolic checklist. The guide to choosing psychiatric care explains how to start.

Frequently asked questions

Which antipsychotic causes the least weight gain?

In a large 2020 analysis of short-term trials, aripiprazole, brexpiprazole, cariprazine, lurasidone and ziprasidone had the most benign metabolic profiles, and olanzapine and clozapine the worst. Individual responses vary, and the right choice also depends on effectiveness and other side effects.

Do I need fasting blood tests on an antipsychotic?

Fasting glucose and lipids are the traditional tests. NICE accepts HbA1c instead of fasting glucose, which does not require fasting. Ask your prescriber which tests they want and whether you need to fast.

Is weight gain on an antipsychotic permanent?

Not necessarily. Weight can sometimes be reduced with lifestyle changes, a medication switch or an add-on medicine such as metformin. Results vary, and changes are easier to address early.

Can low-dose quetiapine for sleep cause metabolic problems?

Quetiapine is not FDA-approved for insomnia, and any antipsychotic can affect weight, glucose and lipids. If you take it for sleep, ask your prescriber whether monitoring is needed and about other sleep options.

Should my primary care doctor or psychiatrist do the monitoring?

Either can, as long as one of them is clearly responsible and both see the results. Agree on who orders the tests at the start.

Does an antipsychotic injection carry the same metabolic risk as the pill?

A long-acting injection contains the same medicine as its oral form, so the same metabolic monitoring applies. Ask your prescriber about the specific product.

Sources

1. Consensus development conference on antipsychotic drugs and obesity and diabetes. American Diabetes Association; American Psychiatric Association; American Association of Clinical Endocrinologists; North American Association for the Study of Obesity. Diabetes Care 27(2):596-601 (PMID 14747245), 2004. pubmed.ncbi.nlm.nih.gov
2. Recommended Monitoring for Patients Taking Second Generation Antipsychotics (SGAs). Carelon Behavioral Health (citing the 2004 ADA/APA consensus and APA guideline watch), 2016. carelonbehavioralhealth.com
3. Comparative effects of 18 antipsychotics on metabolic function in patients with schizophrenia, predictors of metabolic dysregulation, and association with psychopathology: a systematic review and network meta-analysis. Pillinger T et al., Lancet Psychiatry 7(1):64-77 (PMID 31860457), 2020. pubmed.ncbi.nlm.nih.gov
4. Zyprexa (olanzapine) tablets, Zydis and intramuscular prescribing information. Eli Lilly / DailyMed (NLM), 2026. dailymed.nlm.nih.gov
5. Bipolar disorder: assessment and management (CG185), Recommendations. National Institute for Health and Care Excellence (NICE), 2014 (updated 2025). nice.org.uk
6. Lybalvi (olanzapine and samidorphan) prescribing information. Alkermes / DailyMed (NLM), 2026. dailymed.nlm.nih.gov
7. Cobenfy (xanomeline and trospium chloride) prescribing information. Bristol Myers Squibb / DailyMed (NLM), 2026. dailymed.nlm.nih.gov
8. FDA removes risk evaluation and mitigation strategy (REMS) program for the antipsychotic drug clozapine. U.S. Food and Drug Administration (Drug Safety Communication, 27 Aug 2025), 2025. fda.gov
9. Pharmacological interventions for prevention of weight gain in people with schizophrenia. Agarwal SM et al., Cochrane Database of Systematic Reviews CD013337.pub2 (PMID 36190739), 2022. pubmed.ncbi.nlm.nih.gov
10. Pharmacological Interventions for Weight Reduction in Patients With Schizophrenia Treated With Antipsychotics: A Systematic Review and Network Meta-Analysis. Stogios N et al., JAMA Psychiatry 83(9):912-920 (PMID 42418179), 2026. pubmed.ncbi.nlm.nih.gov
11. Monitoring Lipids in Patients Treated With Ziprasidone or Aripiprazole. Khan S, Zacher J. Federal Practitioner 27(11):35-38, 2010. cdn.mdedge.com
12. Metformin hydrochloride tablets prescribing information. DailyMed (NLM), 2026. dailymed.nlm.nih.gov
13. Clozaril (clozapine) prescribing information. HLS Therapeutics / DailyMed (NLM), 2026. dailymed.nlm.nih.gov

Educational information, not medical, tax or legal advice. Decisions about diagnosis, medication and treatment belong with a clinician who knows your history.