Insulin, such as insulin isophane suspension and 70% human isophane suspension/30% human insulin injection, is available over the counter in 49 US states and the District of Columbia. Over-the-counter insulin is banned in Indiana.1 Reports suggest that some patients with diabetes who are uninsured or underinsured purchase Walmart-brand ReliOn (Novo Nordisk) insulin over the counter because it is considerably less expensive ($24.88 per 10-mL vial) than the Novolin (Novo Nordisk) and Humulin (Lilly) insulins sold over the counter at other pharmacies ($152-$163 per 10-mL vial).1-3 Information, however, is lacking to support these reports, and Walmart does not make public its sales data.1 We sought to obtain such information.
In 2018, we conducted a national telephone-based survey of Walmart and chain pharmacies in the 49 states where over-the-counter insulin is sold. In each state, we surveyed 6 Walmart pharmacies (1 in each geographic quadrant of each state and 2 in a central location) and the closest chain pharmacy (CVS, Walgreens, Rite Aid), identified using Google Maps. One of the authors (K.B.) administered a 5-item questionnaire with questions about the frequency of over-the-counter insulin sales and the perceived reasons why patients purchased insulin over the counter. We categorized frequency of sales as daily, weekly, monthly, a few times a year, and never. We asked pharmacies that reported daily over-the-counter insulin sales to estimate the number of vials sold per day. Survey responses were collected in REDCap. Stata software (version 14, StataCorp) was used to generate descriptive and bivariate statistics. The Christiana Care Health System institutional review board approved the study, and participant written informed consent was not required.
Of the 582 pharmacies that were contacted, 561 (96.4%) completed the questionnaire; all 49 states were represented. Among the respondents, 557 (99.3%) self-identified as pharmacists or pharmacy technicians and 4 (0.7%) identified as pharmacy managers or interns. When participants were asked whether the pharmacy sold insulin over the counter/without a prescription, 500 (89.1%) responded “yes” (284 of 292 Walmart pharmacies and 216 of 269 other chain pharmacies).
Among the 284 Walmart pharmacies with over-the-counter sales of insulin, 247 (87.0%) respondents stated that they sold it daily, 31 (10.9%) sold it weekly, 3 (1.1%) sold it monthly, and 3 (1.1%) sold it a few times a year (Figure). Among the other chain pharmacies, 0 sold over-the-counter insulin daily, 3 (1.4%) sold it weekly, 19 (8.8%) sold it monthly, 100 (46.3%) sold it a few times a year, and 94 (34.5%) never sold it (P < .001 for the overall comparison of Walmart and chain pharmacies). When participants were asked whether they were aware of patients who purchased insulin over the counter because they could not afford the copay for their prescription insulin, 223 (54.9%) of the respondents answered yes; 199 (70.1%) positive responses were from Walmart pharmacies and 24 (19.7%) were from chain pharmacies (P < .001).
Walmart pharmacies reported selling a median of 4 vials of insulin over the counter daily (mean, 6 vials; range, 1-50 vials). Based on a total of 4700 Walmart pharmacies in the United States (Walmart spokesperson; written communication; October 25, 2018) and median daily sales of 4 vials, an estimated 18 800 vials of insulin may be sold over the counter daily.
Our national survey provides information about the sale and reasons for purchase of over-the-counter insulin. Although our data represent perceptions of pharmacy employees rather than actual sales data, they support an estimate of daily sales of more than 18 000 vials of over-the-counter insulin at Walmart pharmacies. Our finding that over-the-counter insulin is sold more commonly at Walmart than at other chain pharmacies likely reflects the fact that the Walmart brand is considerably less expensive than other brands of insulin sold at chain pharmacies.1-3 Inability to afford copays for prescription insulin was noted as a common reason for purchase, particularly at Walmart pharmacies. Further studies should explore clinical and safety outcomes related to the use of over-the-counter insulin.
Accepted for Publication: October 29, 2018.
Published Online: February 18, 2019. doi:10.1001/jamainternmed.2018.7279
Corresponding Author: Jennifer N. Goldstein, MD, MSc, Christiana Care Health System, Department of Medicine, 4755 Ogletown Stanton Rd, Ammon Education Bldg, Ste 2E70, Newark, DE 19718 (jgoldstein@christianacare.org).
Author Contributions: Dr Goldstein and Ms Bland had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Goldstein, Hicks.
Acquisition, analysis, or interpretation of data: Goldstein, Patel, Bland.
Drafting of the manuscript: All authors.
Critical revision of the manuscript for important intellectual content: Goldstein, Hicks.
Statistical analysis: Goldstein, Patel, Bland.
Administrative, technical, or material support: Goldstein, Hicks.
Study supervision: Goldstein, Hicks.
Conflict of Interest Disclosures: None reported.
Funding/Support: Ms Bland was supported by the National Institutes of Health/National Institute of General Medical Sciences Institutional Development Award program grant P20 GM103446.
Role of the Funder/Sponsor: The funder had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.