Biologic drugs for rheumatoid arthritis are given in two main ways: as injections you give yourself at home (subcutaneous) or as intravenous infusions at a clinic. Most biologics on the market today use one of these two routes, and a few, like abatacept and tocilizumab, are available in both forms with no difference in effectiveness between them.
Self-Injection at Home
The majority of biologics for RA are delivered as subcutaneous injections, meaning a short needle deposits the medication into the fatty tissue just beneath the skin. These are typically given every one to two weeks, depending on the specific drug. You’ll use either a prefilled syringe or an autoinjector pen, both of which come preloaded with the correct dose.
Autoinjector pens are the more popular choice. In head-to-head comparisons, 94.5% of patients found the autoinjector easy or extremely easy to use, compared with 73.6% for the prefilled syringe. Discomfort was also less common: only 5.5% of autoinjector users reported moderate discomfort or worse, versus about 21% of syringe users. No autoinjector users reported pain severe enough to discourage future self-injection, while nearly 9% of syringe users did. If you have a strong preference for one format over the other, it’s worth asking whether your prescribed biologic comes in both.
The recommended injection sites are the front of your thighs, your belly (at least two inches from the navel), and the outer back of your upper arms. You should rotate sites with each injection, keeping at least one inch between spots. Before injecting, wash your hands thoroughly and clean the skin with an alcohol pad, wiping outward in a circle and letting it air dry.
IV Infusions at a Clinic
Some biologics are given through an intravenous drip, which requires a visit to an infusion center or your rheumatologist’s office. Three commonly infused biologics for RA are infliximab, rituximab, and abatacept (though abatacept also comes in a subcutaneous form). Infusion sessions typically last 30 minutes to a few hours depending on the drug, and a nurse monitors you during and shortly after the process.
The scheduling varies considerably by drug. Abatacept infusions are given roughly every four weeks. Infliximab follows a loading schedule at the start (doses at weeks 0, 2, and 6) and then settles into an every-eight-week cycle. Rituximab has the longest gap: it’s given as two doses separated by two weeks, and those two-dose courses are repeated about every six months. In real-world data, patients averaged 6.8 months between rituximab courses.
Some people actually prefer infusions because they don’t have to think about self-injecting. Others find the clinic visits disruptive. If you’re on a drug that comes in both IV and subcutaneous forms, switching between them is considered safe and effective. Some patients on abatacept, for example, temporarily switch from weekly self-injections to a single monthly infusion to cover a vacation.
What Biologics Target
Biologics work by blocking specific parts of the immune system that drive joint inflammation. They fall into several categories based on their target:
- TNF blockers (infliximab, etanercept, adalimumab) neutralize a protein called tumor necrosis factor alpha, one of the primary drivers of inflammation in RA. This is the largest and most established class.
- IL-6 blockers (tocilizumab) shut down signaling from interleukin-6, another inflammatory protein that contributes to joint damage and systemic symptoms like fatigue.
- B-cell depleters (rituximab) reduce the population of B-cells, a type of immune cell that plays a key role in producing the antibodies that attack joint tissue.
- T-cell modulators (abatacept) prevent the full activation of T-cells, another immune cell type that orchestrates the inflammatory response in RA.
Your rheumatologist will typically choose a class based on your disease activity, previous treatment history, and other health conditions. TNF blockers are often tried first, with other classes reserved for people who don’t respond adequately.
Why Biologics Are Usually Paired With Methotrexate
Most people starting a biologic will also continue taking methotrexate, a conventional disease-modifying drug given as a weekly pill or injection. This isn’t just habit. Systematic reviews and network analyses show that combining a biologic with methotrexate improves disease control, remission rates, and physical function compared with using either drug alone. Patients on combination therapy were 20% to 57% more likely to achieve a meaningful reduction in symptoms than those on methotrexate by itself.
There’s no reliable way to predict in advance who might do well on methotrexate alone versus who needs the addition of a biologic. In practice, most rheumatologists start methotrexate first and add a biologic if the response isn’t sufficient within three to six months.
Screening Before You Start
Before your first dose, you’ll go through a screening process. Because biologics suppress parts of the immune system, your doctor needs to check for latent infections that could reactivate once your immune defenses are lowered. Tuberculosis screening is standard for all biologics and is strongly recommended by multiple medical organizations. This involves a blood test (called an interferon-gamma release assay) or a skin test. If you were born outside the U.S., have traveled to a TB-endemic area for more than 30 days in the past year, or have had close contact with someone with active TB, you may need a second confirmatory test. Screening for hepatitis B is also typical before starting treatment.
Injection Site Reactions and Side Effects
The most common side effect of subcutaneous biologics is a local reaction at the injection site. In a large meta-analysis of clinical trials, redness accounted for about 43% of all reported injection site reactions, followed by pain (12%) and itching (6%). Swelling, bruising, and small lumps under the skin occur in a smaller percentage of cases. These reactions are generally mild and resolve on their own within a day or two.
Less commonly, some people experience flu-like symptoms after an injection or infusion, including low-grade fever, fatigue, and muscle aches. This happens when the drug triggers a burst of inflammatory signaling molecules, and it tends to improve with subsequent doses as the body adjusts. Serious allergic reactions during IV infusions are possible but rare, which is why infusion centers keep you under observation.
The broader concern with all biologics is a modestly increased risk of infection, since these drugs deliberately dial down immune activity. Serious infections are uncommon but do occur, which is why the pre-treatment screening matters and why your care team will monitor blood work periodically.
Storing Biologics at Home
If you self-inject, you’ll keep your medication in the refrigerator, typically between 2°C and 8°C (36°F to 46°F). Each drug has its own rules for how long it can stay at room temperature if needed. Adalimumab can be kept at up to 25°C (77°F) for a limited period. Etanercept is stable at room temperature for up to 30 days. Tocilizumab can sit at up to 30°C for up to 14 days. Once a biologic has been out of the fridge beyond its allowed window, it should be discarded, not re-refrigerated.
Many people let their injection warm to room temperature for 15 to 30 minutes before using it, since cold medication tends to sting more going in. Just don’t use a microwave or hot water to speed this up, as heat can damage the protein structure of the drug.
Biosimilars as a Lower-Cost Option
Biosimilars are near-identical copies of original biologic drugs, approved by the FDA after demonstrating equivalent safety and effectiveness. Several biosimilars are now available for the most commonly prescribed RA biologics, and they’re given the same way as their reference products: same injection sites, same infusion schedules, same doses. The primary advantage is cost. If your insurance or pharmacy offers a biosimilar version of your prescribed biologic, the administration experience will be essentially the same.