Weight Loss Products
(Modified May 2023)
Multiple products are approved
for weight loss. For information about patients requiring bariatric surgery for weight
loss, see our chart, Bariatric Surgery
and Medication Use. The chart below
reviews pertinent information about use of approved weight-loss products, including dosing, expected weight loss, cost, and considerations for
use.
Producta,f |
Usual Dosea |
Mean Weight Lossa,b |
Costc and Considerations for Usea |
Products that work as a sympathomimetic, anorectic, or to reduce appetited
|
|||
Diethylpropion |
For short-term use (a few weeks)e in patients 16 years and older:
Discontinue if tolerance develops or if not effective after four weeks (e.g., <1.8 kg [4 pounds] lost). |
~3 kg (6.6 pounds) |
Cost: ~$1.25/day Monitor for increases in BP and HR. Discontinuation rate due to adverse effects: unknown. |
Phentermine |
For short-term use (a few weeks)e in patients 17 years and older:
Discontinue if tolerance develops or if not effective after a few weeks (e.g., <1.8 kg [4 pounds] lost). |
Adipex-P:
Lomaira: unknown (assumed similar to other phentermine products) |
Cost:
Monitor for increases in BP and HR. Discontinuation rate due to adverse effects: unknown. |
Phentermine/ Provide a MedGuide with each Rx. Pharmacies must enroll and be certified to dispense. REMS info at www.qsymiarems.com. |
For patients 12 years and older:
|
~9 kg (19 pounds) ~70% of patients met weight loss goal (≥5%) at one year compared to 21% with placebo. |
Cost: ~$6.50/day Monitoring for (due to topiramate):
Discontinuation rate due to adverse effects: one out of every 14 patients. |
Products that work as a glucagon-like peptide-1 (GLP-1) receptor agonist to reduce appetite and food/calorie intake
|
|||
Liraglutide Provide a MedGuide with each Rx (U.S.) |
For patients 12 years and older:
|
~3.7 to 5.2 kg ~44% to 62% of patients met weight loss goal (≥5%) at 56 weeks compared to 16% to 34% with placebo. |
Cost:
Discontinuation rate due to adverse effects: one out of every 18 patients. |
Semaglutide Provide a MedGuide with each Rx *Approved in Canada, but not yet marketed at time of publication |
For patients 12 years and older (18 years and older in Canada):
|
~10.6 to 12.7 kg (22 to 27 pounds) (2.4 mg once weekly at one year)2,10 67% to 85% of patients met weight loss goal (≥5%) at 52 weeks compared to 30% to 48% with placebo.2,10 |
Cost:
Discontinuation rate due to adverse effects: one out of every 28 patients. |
Product that works to inhibit GI lipase to prevent fat absorption |
|||
Orlistat |
For patients 12 years and older:
For patients 18 years and older:
Recommend an MVI with A, D, E, K, and beta-carotene at bedtime or ≥2 hours before or after orlistat. |
Xenical (120 mg TID):
Alli (60 mg TID): ~2 kg (~4.4 pounds) at 24 weeks7 |
Cost:
May reduce absorption of vitamin K and certain meds. See product labeling for specifics (e.g., timing, monitoring, dose adjustments). Recommend additional contraception if patients experience severe diarrhea (possible reduced absorption of oral contraceptives [Canadian labeling]). Discontinuation rate for Xenical due to adverse effects: one out of every 26 patients. |
Product that works to reduce appetite and cravings9 |
|||
Naltrexone 8 mg/ Provide a MedGuide with each Rx (U.S.) |
For patients 18 years and older:
|
≤4.1 kg (9 pounds) 36% to 57% of patients met weight loss goal (≥5%) at 56 weeks compared to 17% to 43% with placebo. |
Cost: ~$10/day (U.S. and Canada) Associated with CYP drug interactions. See product labeling for specifics. Avoid in patients taking opioids (due to naltrexone). Monitor for increases in BP, HR, and suicidal thoughts/behavior (due to bupropion). Discontinuation rate due to adverse effects: one out of every nine patients. |
Product that works as a melanocortin 4 (MC4) receptor agonist to reduce appetite |
|||
Setmelanotide |
For patients 6 to 11 years old:
For patients 12 years and older:
Discontinue after 12 to 16 weeks at full dose if <5% weight loss achieved. |
80% of patients with POMC or PCSK1 deficiency or 46% of patients with LEPR deficiency achieved ≥10% weight loss at one year. |
Cost: not available at time of publication Approved in patients with obesity due to genetic testing confirmed-deficiency of one of the following:
Discontinuation rate due to adverse effects: unknown. |
Product (nonabsorbable cellulose/citric acid hydrogel) that works to promote a sense of fullness by occupying space in the stomach |
|||
Plenity, U.S. only Particles absorb water in the stomach to create sense of fullness. The water is reabsorbed in the colon and the particles are eliminated via bowel movements. Note: Plenity is considered a device, not a drug, because it is not absorbed or metabolized by the body. |
Only available through telehealth visitsg (https://www.myplenity.com/) for patients 18 years and older:
|
~2% at six months ~59% patients met weight loss goal (5%) at six months compared to 42.2% with placebo. |
Cost: $3.50/day (~$1.75/meal).6 Expanded particles occupy ~25% of the stomach. The effect of Plenity on most meds is unknown.
Avoid use in patients with certain GI abnormalities or conditions. See product labeling for a complete list. GI adverse effects are common (e.g., diarrhea, bloating, nausea, vomiting, constipation).2 Discontinuation rate due to adverse effects: appears similar to placebo. |
- Information from product labeling, unless otherwise noted. U.S. product labeling: diethylpropion extended-release (Lannett Company, December 2019); diethylpropion hydrochloride tablet (KVK-tech, December 2018); Adipex-P (September 2020); Lomaira (December 2018); Saxenda (December 2020); Wegovy (December 2022); Xenical (January 2018); Alli (November 2020); Contrave (August 2020); Qsymia (June 2022); Imcivree (November 2020); Plenity (April 2019). Canadian product labeling: Saxenda (February 2021); Xenical (September 2017); Contrave (May 2020).
- Mean weight loss with lifestyle changes and/or diet. Weight loss is the amount above that seen with placebo. Weight loss varies based on lifestyle modification, baseline weight, etc.
- Pricing (for generic when available) based on wholesale acquisition cost (WAC). U.S. medication pricing by Elsevier, accessed July 2021. Discount programs may be available for some drugs.
- Older amphetamines indicated for weight loss (e.g., benzphetamine [U.S.], methamphetamine [U.S.], phendimetrazine [U.S.]) are not included in the chart. However, adverse effects, contraindications, and cautions are similar to diethylpropion and phentermine. Product labeling should be consulted for more specific information.
- Though product labeling may specify use should be limited to a few weeks, guidelines suggest that if weight loss from an approved medication is at least 5% at 12 weeks, medications can be continued.4
- Lorcaserin (Belviq, Belviq XR, U.S. only) was withdrawn from the market (February 2020) due to increased occurrence of cancer in clinical trials.8
- Plenity is anticipated to be available outside of these telehealth visits sometime during 2021.
Abbreviations: GI = gastrointestinal; BID = twice daily; BP = blood pressure; CR = controlled-release; ER = extended-release; HR = heart rate; IR = immediate-release; PO = orally; TID = three times daily; QID = four times daily.
References
- Li Z, Maglione M, Tu W, et al. Meta-analysis: pharmacologic treatment of obesity. Ann Intern Med 2005;142:532-46.
- Wilding JPH, Batterham RL, Calanna S, et al. Once-weekly semaglutide in adults with overweight or obesity. N Engl J Med 2021;384:989.
- Hendricks EJ, Greenway FL, Westman EC, Gupta AK. Blood pressure and heart rate effects, weight loss and maintenance during long-term phentermine pharmacotherapy for obesity. Obesity (Silver Spring) 2011;19:2351-60.
- Apovian CM, Aronne LJ, Bessesen DH, et al. Pharmacological management of obesity: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2015;100:342-62.
- MyPlenity.com. Weight management without deprivation. https://www.myplenity.com/healthcare-professionals. (Accessed July 7, 2021).
- MyPlenity.com. Frequently asked questions. https://www.myplenity.com/faq. (Accessed July 7, 2021).
- Smith SR, Stenlof KS, Greenway FL, et al. Orlistat 60 mg reduces visceral adipose tissue: a 24-week randomized, placebo-controlled, multicenter trial. Obesity (Silver Spring) 2011;19:1796-803.
- FDA. FDA drug safety communication. FDA requests the withdrawal of the weight-loss drug Belviq, Belviq XR (lorcaserin) from the market. February 13, 2020. https://www.fda.gov/media/135189/download. (Accessed July 7, 2021).
- Caixas A, Albert L, Capel I, Rigla M. Naltrexone sustained-release/bupropion sustained-release for the management of obesity: review of the data to date. Drug Des Devel Ther 2014;8:1419-27.
- Wadden TA, Bailey TS, Billings LK, et al. Effect of subcutaneous semaglutide vs placebo as an adjunct to intensive behavioral therapy on body weight in adults with overweight or obesity: the STEP 3 randomized clinical trial. JAMA 2021;325:1403-13.
- Lajthia E, Bucheit JD, Nadpara PA, et al. Combination therapy with once-weekly glucagon like peptide-1 receptor agonists and dipeptidyl peptidase-4 inhibitors in type 2 diabetes: a case series. Pharm Pract (Granada) 2019;17:1588.
Cite this document as follows: Clinical Resource, Weight Loss Products. Pharmacist’s Letter/Prescriber’s Letter. August 2021. [370802]