For many people, the least-expensive way to take insulin is using a needle, syringe, and vial, because these supplies are most likely to be covered under Medicare, state Medicaid plans, and private insurance than other injection methods, according to a study published in European Endocrinology. But syringe delivery is also the most painful and difficult method, with a higher risk of dosing errors and hypoglycemia (low blood sugar) episodes than other methods. People who use pumps have insulin delivered to them 24 hours a day in a manner that mimics the body’s own way of releasing insulin. Yet pump delivery can be expensive — costing as much as $4,500 for the device without insurance, an additional $1,500 per year in supplies, according to an article published in The American Journal of Managed Care. With insulin pens, a cartridge of insulin is contained within the pen (it may be prefilled or need to be inserted), the dosage is dialed on the pen, and then insulin is injected beneath the skin through a needle. To get the full dose, the pen needle should be “primed” with each use, the knob of the pen must be pushed all the way in and held at the injection site for 6–10 seconds before the needle is pulled out. (The Cleveland Clinic provides detailed instructions on how to inject yourself properly with a pen.) According to GoodRx, pens containing 300 units of insulin can cost between $72 and $254 per pen, though what you’ll ultimately pay depends on the insulin you’re using. In general, pen users tend to spend more than syringe users, but that can be in part because they are more likely to use pricier analogue (synthetic) insulins and to inject more units of insulin per day, notes the aforementioned study in European Endocrinology. RELATED: What to Ask Your Doctor if You’re New to Using Basal Insulin “First, there is no need for complex maneuvering to draw the insulin out of a vial. In addition, the final dose to be administered is a lot easier to see with a pen because of the relatively large numbers featured in the dosing window, rather than counting tick marks on a syringe. Lastly, many of the newer insulin formulations are now available in unique concentrations, which are unsafe to administer with a traditional syringe because of the need for additional calculations to administer the correct dose. Not everyone prefers to use an insulin pen, but those who do find it easier and much more convenient to use than the traditional vial and syringe.” People who inject insulin also find pens to be less painful, more convenient, and easier to use than syringes, according to a review in the Journal of Diabetes Science and Technology. Yet as it stands, a slim majority of the 7.4 million people who inject insulin in the United States opt for vials and syringes, according to an article published in Diabetes Care. HCCI reports that vials made up 53 percent of insulin usage in 2016, followed by prefilled insulin pens at 46 percent. Cartridges that go with reusable pens represent less than 1 percent of insulin used annually. A study published in the Journal of Clinical Medicine estimated that 350,000 people use pumps in the United States. By comparison, in Europe pens make up about 80 percent of insulin usage, according to a review published in the International Journal of Pharmaceutical Investigation. Despite the higher costs upfront, pen injections may save people more money than syringes. A study of low-income Medicaid recipients with type 2 diabetes showed lower overall healthcare costs for those who switched from syringes to insulin pens because overall healthcare service usage was lower. The study authors theorized that more accurate dosing (and therefore better blood glucose control) may have been among the reasons why. The insulin is delivered through needles that range from 4 to 12.7 millimeters in length, and thickness (gauge) that can range from 29 (thicker) to 33 (thinner), according to a consumer guide released by the magazine Diabetes Forecast. A thicker needle is capable of giving a dose of insulin more rapidly, while a thinner needle is less painful to use. RELATED: 10 Ways You May Be Sabotaging Your Insulin Therapy

Disposable Insulin Pens

These come with prefilled insulin cartridges. The entire pen is discarded after all the insulin has been used. Here are some examples of disposable insulin pens and their price estimates per GoodRx:

A Humalog U-100 Kwikpen ($133 per pen, or $0.44 per unit) contains 300 units of fast-acting (mealtime) insulin lispro.A Toujeo Max SoloStar ($160 per pen, or $0.35 per unit) contains 900 units of long-acting insulin glargine that is taken once a day.

Reusable Insulin Pens

These come with replaceable cartridges and are meant to last years. For example, a NovoPen 4 uses 3 mL Penfill cartridges of Novo Nordisk insulins, such as 300 units of fast-acting NovoLog insulin aspart per cartridge ($130 per cartridge, or $0.47 per unit, according to GoodRx). The pen can be purchased online, and the company says it is designed to last up to five years.

‘Smart’ or ‘Connected’ Insulin Pens

Generally, reusable pens are able to record and transmit data wirelessly and are often paired with a mobile app or a continuous glucose monitor (CGM). Functions vary by pen, but the most integrated smart pens log glucose level, carbohydrate intake, and the number of insulin doses administered, says Dr. Bzowyckyj. “Many of these insulin pens sync with an app via Bluetooth technology to help log a lot of these important elements of a person’s care plan,” says Bzowyckyj. “Many times, I hear patients say they may not remember if they administered their insulin dose before a meal for a variety of reasons, which then stresses them out because they do not want to double dose and risk hypoglycemia [low blood sugar]. Not only can insulin pen technology help document doses administered, but it can also help patients determine the best dose to administer by factoring in variables such as anticipated carbohydrate intake, active insulin time, and current and goal glucose levels.” The apps may also track additional health data, such as patient weight and steps or physical activity, either by syncing with a fitness tracker or when the user manually logs in the data, Bzowyckyj adds. “My patients love smart pens,” says Diana Isaacs, PharmD, CDCES, a clinical pharmacy specialist at the Cleveland Clinic Diabetes Center in Ohio who is a spokesperson for the Association of Diabetes Care and Education Specialists. “For any patient of mine who takes mealtime insulin and prefers not to use an insulin pump, this is a great option and one that I encourage.” RELATED: A Complete Guide to Using Basal Insulin

Tips for Using Insulin Pens Safely

Insulin pens that are in use can be refrigerated or kept at room temperature (between 56 degrees F and 80 degrees F) and discarded after the manufacturer-listed number of days has elapsed, according to GoodRx. Often that is 28 to 30 days, but check the instructions to be certain. Unused pens can be kept refrigerated (at a temperature of 36 degrees F to 46 degrees F) and then warmed to room temperature when you are ready to use them. Once they are outside the fridge, the expiration date no longer applies. Keep in mind that cartridges and prefilled pens only contain one type of insulin. Two separate injections must be given with different insulin pens if one is using two types of insulin. And you should never share an insulin pen, warns the Centers for Disease Control and Prevention. Also, never use a syringe to withdraw insulin from a pen or cartridge, which can lead to dosing errors when the pen is used again, advises the NHS. RELATED: Insulin Supplies: 6 Mistakes You May Be Making

Disposable pens in 200 unit per mL and 300 unit per mL concentrationsThe ability to administer partial units for more highly customized dosesMemory functions that allow users to keep track of when they took insulinA dose calculator that allows people to more accurately determine how much insulin they need in a given situationThe ability to integrate CGM data into a pen

Here’s a closer look at these developments.

Newer Concentrated Insulins

“We’ve seen tremendous improvements in using pens to dose concentrated insulin,” says Miller, who is the medical director of diabetes care at Stony Brook Medicine in Stony Brook, New York. “The pharmaceutical industry has gotten better at packaging those insulins in a safer way to be able to dose the amount of insulin that the patient needs.” Patients who require higher doses of insulin than the traditional U-100 concentration because they have obesity or have insulin resistance only had U-500 insulin to turn to until recently. U-500 insulin also was previously only available as a vial; now it’s available as a pen, further facilitating dose calculation. “At five times the concentration of traditional insulin, it’s very dangerous in an inappropriate amount and without accurate dosing,” he explains. According to the aforementioned review in Therapeutics and Clinical Risk Management, newer pens on the market within the last few years contain varying concentrations of long-lasting (basal) insulin, such as a Tresiba FlexTouch pen with 3 mL of U-200 insulin degludec ($248 per pen, or $0.41 per unit); or a Toujeo Max SoloStar pen with 3 mL of U-300 insulin glargine ($315 per pen, or $0.35 per unit) — prices all according to GoodRx. “As a result of the wider availability of some of the concentrated long-lasting insulins, like U-200, patients are able to absorb the insulin in a much more predictable way, and their basal insulin requirements are met more reasonably, accurately, and effectively,” says Miller.

Administering Partial Units

The ability to give half-unit doses is another exciting development, according to Bzowyckyj. Those who are especially sensitive to insulin (such as children and seniors, according to a review published in the Journal of Diabetes Science and Technology) and who use low amounts may be more prone to dosing errors. Half-unit functionality, such as that available in the Humalog Junior KwikPen ($129 per pen, or $0.34 per unit according to GoodRx) and the NovoPen Echo, makes it easier to deliver just the right amount of insulin.

Memory Functions

“For me, the most exciting new development is the dose memory functionality, which keeps track of the doses and times of insulin doses that a person self-administered recently,” Bzowyckyj continues. “Oftentimes, it is easy for people to forget whether or not they administered their medications, especially with how hectic our lives can get. With traditional tablets and capsules, people can just check their pillbox to see if today’s space is empty, but unfortunately, that is not an option with insulin. The dose memory feature is a great way to prevent a person from double dosing their insulin.” Among the smart pens with memory functionality is the NovoPen Echo 5. Its half-increment dosing uses 3 mL Penfill cartridges of Novo Nordisk insulins, such as 300 units of fast-acting NovoLog insulin aspart per cartridge ($130 per cartridge, or $0.47 per unit, according to GoodRx). The pen can cost as little as about $37 in some pharmacies but may be more expensive depending on your pharmacy, according to WellRx. Another example is Companion Medical’s InPen, which is compatible with Humalog and Novolog U-100 3 mL insulin cartridges. Prices vary by pharmacy, but the InPen for Humalog and the Novolog version can also cost around $37.

Dose Calculator

Isaacs’s patients use the InPen, which she prefers to the NovoPen Echo 5. “Currently, the Novo Echo has a dosing recorder but lacks the other advanced features of the InPen,” says Isaacs. For instance, with the InPen, “There is a dosing calculator embedded in it, which makes calculations much easier,” she says. “The calculator makes it much easier to add the insulin needed for a given amount of carbohydrates and a certain glucose level. It also may subtract active insulin from a previous dose that is still working in the body through an advanced calculation.” That last function is one that Miller points out as being especially useful for avoiding dosing errors.

CGM Integration

Isaacs is excited about upcoming developments that will allow dosing data from smart pens to be shared with continuous glucose monitors (CGMs), such as a Freestyle Libre, Medtronic Guardian, and Dexcom G6. The CGMs use a sensor wire inserted under the skin and a small, portable transmitter to send data to a receiver or smart device 24 hours a day. They are typically used by people with type 1 diabetes and are especially useful for those who are at risk for hypoglycemia and either don’t recognize the signs or experience them overnight, according to the National Institute of Diabetes and Digestive and Kidney Diseases, though doctors are seeing more people with type 2 diabetes who are starting to use CGMs. Last year it was announced that Medtronic devices would integrate with future Novo Nordisk smart insulin pens beginning in 2020, and the Freestyle Libre would integrate with future insulin smart pens by Novo Nordisk and Sanofi (maker of the Lantus Solostar insulin glargine pen). Previously it was announced that the Dexcom G6 would integrate with upcoming Novo Nordisk smart insulin pens. Despite all these developments, many insulin users aren’t even aware that smart pens exist, according to Isaacs. Miller doesn’t see growing awareness necessarily translating into wider adoption of smart pens at all. Instead, he predicts that over time those insulin users who are interested in technological improvement are more likely to move over to pump therapy rather than smart pens. “The patients I have who don’t want to go on a pump tell me that they want to stay on a [traditional] pen because the pens are simple. They are easier to use and they don’t have to think about numbers and data. They just dial the dosage, they take it, and they are done.” He also sees affordability as another barrier to wider adoption. “Outside of rebate programs and coupons, company certificates and the like, I have not heard of robust insurance coverage from the managed-care and insurance companies to cover electronic pens over the cost of a traditional insulin pen.” In 2019, Companion Medical announced a program to ensure that InPen users with commercial insurance will pay no more than $99 annually for the device, which is designed to last a year. RELATED: FDA Approves First Implantable CGM for People With Type 1 and Type 2 Diabetes

What are my insulin delivery options?What options will insurance cover?Would I benefit from having a dosing calculator to help calculate insulin doses?Would I benefit from a pen that helps keep track of all insulin doses?Would I benefit from a pen that knows when a previous insulin dose is still working in my system?

Insurance coverage will likely drive your choice, says Bzowyckyj. If you have multiple options, consider dexterity (some pens are spring-loaded while others require the ability to extend your thumb to administer the dose), whether you’ll need to administer partial doses, and whether you prefer a disposable pen or a reusable pen that has disposable cartridges, he says. “Not everyone prefers to use an insulin pen, but those who do find it easier and much more convenient to use than the traditional vial and syringe,” he says.