Understanding IVIG and SCIG Treatments

Written by Drew Doyle, RPh, Executive Vice President, Sales and Market Development at Soleo Health

If you or a loved one receives immunoglobulin (Ig) therapy, you may have heard the terms IVIG and SCIG, but what do they really mean?

The difference in how these therapies are given is similar to different routes of travel: IVIG is delivered through a vein, much like a bustling highway, allowing swift movement directly into the bloodstream. SCIG, on the other hand, is infused just under the skin, akin to a peaceful side street, providing a steady yet gentle journey through the body’s defenses.

In this blog, we’ll break down the key differences between IVIG (intravenous immunoglobulin) and SCIG (subcutaneous immunoglobulin) so you can feel more confident about your treatment choices.

What is Immunoglobulin Therapy?

When someone has an autoimmune condition, their immune system mistakenly attacks their own healthy cells, tissues, or organs.

Immunoglobulin therapies are primarily used to treat immune deficiencies and various autoimmune conditions, helping the body regulate or support its immune response.

What Does Immunoglobulin (Ig) Therapy Do?

Imagine your immune system as a security team that’s short-staffed and running on outdated equipment. Immunoglobulin therapy is like sending in a highly trained special ops team to strengthen your body’s natural defenses. In some cases, the special ops team calms down the body’s natural defenses.

Immunoglobulin (Ig) therapy provides antibodies your body needs to help fight infections or calm an overactive immune system. The healthy antibodies are donated from human plasma.

Antibodies can strengthen the immune system for people who don’t make enough of their own antibodies due to a primary immune deficiency (PID).

What Conditions Are Treated With Immunoglobulin Therapy?

Ig therapy can also help calm an overactive immune response in certain autoimmune conditions, such as CIDP, MMN, ITP, Kawasaki disease, and dermatomyositis.

In both cases, Ig therapy helps restore balance in the immune system and reduces the risk of complications related to infection or inflammation.

A woman’s arm while getting an infusion

What is IVIG Therapy?

IVIG (Intravenous Immunoglobulin) is infused directly into a vein, usually by a nurse in a clinic or sometimes at home.

How is IVIG Administered?

Because IVIG treatment is delivered directly into your bloodstream, the infusion can take several hours.

It is typically done only once every three to four weeks.

Many people prefer the convenience of fewer treatments each month, although infusions can take longer and may cause temporary side effects, such as fatigue or headaches.

How Often Are IVIG Treatments Given?

  • Sessions usually last 2–6 hours, depending on the dose
  • Treatments are typically scheduled every 3–4 weeks
  • Close monitoring by a healthcare professional is required

Common Side Effects of IVIG Treatment

  • Headache, fatigue, fever, or nausea
  • Local irritation at the IV site 

Serious, but Rare IVIG Side Effects

  • Serious risks such as anaphylaxis, blood clots, and kidney problems
  • Pre-medication is often given before IVIG infusions to reduce side effects
Skin subcutaneous Injection diagram illustration

What is SCIG Therapy?

SCIG (Subcutaneous Immunoglobulin) is infused just under the skin—often in the abdomen, thighs, or upper arms using a small needle connected to a pump.

Depending on the prescribed dose, treatment may involve one or multiple infusion sites during a session.

How is SCIG Administered?

This method allows you to self-administer treatments at home after proper training.

Because the medication absorbs slowly, it provides steady protection and may cause fewer whole-body side effects for some patients.

How Often are SCIG Treatments Given?

  • SCIG is usually given more frequently, such as weekly or bi-weekly
  • The sessions are shorter and can be done on your own schedule, allowing you to integrate them seamlessly into your daily routine

For instance, you might fit a session in on a quiet Sunday evening between brunch and watching your favorite football game, offering much greater flexibility.

The young man and female doctor sit on the hospital room couch and review the medical chart together.

What is the Difference Between IVIG and SCIG?

  • The primary difference is the delivery route. IVIG is infused directly into a vein
  • SCIG is administered under the skin using small needles (sometimes at multiple sites at once)
  • Both approaches deliver immunoglobulin therapy to support the immune system
  • Both IVIG treatment and SCIG treatment are highly effective options for immune deficiency and certain autoimmune conditions
  • They use the same core medication, purified antibodies from plasma donations, but differ in delivery method and formulation

SCIG Therapy Expectations

  • Typically administered weekly, though schedules may vary
  • Sessions last 1–2 hours, depending on the dose and number of infusion sites
  • Patients can often administer at home after proper training

Common Side Effects of SCIG Therapy

  • Local injection-site reactions such as redness, swelling, or tenderness
  • Mild effects like fatigue or flu-like symptoms (less common than with IVIG)

Who is a Good Candidate for IVIG Therapy?

  • Patients who require higher doses that would be impractical to give subcutaneously
  • Those who prefer fewer treatment sessions
  • Patients who are uncomfortable with self-injection
  • Individuals who benefit from administration in a clinical setting

Who is a Good Candidate for SCIG Therapy?

  • Patients who want greater independence and flexibility
  • Individuals who experience certain side effects with IVIG
  • Patients with difficult IV access
  • Those who prefer home-based treatment on a more flexible schedule
Woman, question and thinking in studio for confused mockup, planning and wonder or inspiration for solution. Brazilian model, doubt and option with emoji, ask and choice with idea by blue background

Choosing Between IVIG and SCIG Therapy

The decision between IVIG and SCIG is typically based on patient-specific factors rather than meaningful differences in overall effectiveness.

IVIG treatment results in higher antibody levels immediately after infusion, which gradually decline before the next session.

SCIG treatment may provide more stable antibody levels due to smaller, more frequent doses.

Frequently Asked Questions About IVIG and SCIG Treatments

Do All Immunoglobulin Therapies Come in IVIG and SCIG Forms?

Do All Immunoglobulin Therapies Come in IVIG and SCIG Forms?

Not all immunoglobulin therapies are available in both IVIG and SCIG forms.

Some products are formulated only for IV use (IVIG); these have a different composition and concentration that make them safe for intravenous infusion only.

Others are formulated only for subcutaneous use (SCIG); they’re more concentrated and designed to be absorbed slowly under the skin.

A few products are approved for both IVIG and SCIG administration, but that’s less common.

Which Treatment is Easier, IVIG or SCIG?

Which Therapy is Easier, IVIG or SCIG?

The ease of IVIG versus SCIG varies from person to person. Each method has its own process, schedule, and unique considerations.

Individuals may find one approach more manageable than the other depending on their specific needs, comfort level, and daily routine.

Your care team can help you understand what to expect from both options, so you can determine which one may best fit your situation.

How Often Do I Need IVIG or SCIG Treatments?

How Often Do I Need IVIG or SCIG?

IVIG treatments are typically given every 3–4 weeks and take about 2–6 hours per session.

SCIG treatments are usually administered weekly and take about 1–2 hours, though both the timing and number of infusion sites may vary based on your prescribed dose.

Can I do SCIG Treatments at Home?

Can I do SCIG Treatments at Home?

Yes. Many patients are able to self-administer SCIG at home after receiving proper training from a healthcare professional. This can offer added flexibility and independence for some individuals.

Is IVIG Treatment as Effective as SCIG Treatment?

Is IVIG Treatment as Effective as SCIG Therapy?

Yes. Research shows that both IVIG and SCIG treatments are effective in preventing infections and supporting immune health.

The choice between them is usually based on individual factors such as lifestyle, dosing needs, and personal comfort with the administration method.

Can Patients Switch From IVIG to SCIG?

Can Patients Switch From IVIG to SCIG Therapy?

Switching is often possible, but it must be guided by your prescriber and depends on several factors:

  • Your diagnosis (e.g., primary or secondary immunodeficiency, CIDP)
  • Your current dose and response to IVIG
  • Product selection and insurance coverage
  • Your comfort with or ability to perform self-administration

If you transition to SCIG, the total monthly immunoglobulin amount typically remains the same but is divided into smaller, more frequent doses to maintain steady levels.

A nurse or specialty pharmacy clinician will provide training on self-infusion and help adjust your regimen during the transition.

Are IVIG and SCIG the Same Medication?

Are IVIG and SCIG the Same Medication?

Both IVIG and SCIG deliver immunoglobulin into the body. Immunoglobulins circulate and support the immune system. 

While both treatments are effective, they differ in how they’re administered and how quickly they take effect.

How Does Immunoglobulin Support the Immune System?

How Does Immunoglobulin Support the Immune System?

For people with immune deficiencies, it provides necessary antibodies. For autoimmune conditions, it helps regulate the immune response and reduce inflammation.

Patient Education Video

 

How to Administer Your Subcutaneous IG Infusion

In this step-by-step video, you’ll learn how to safely and confidently administer your subcutaneous immunoglobulin (IG) infusion at home. From preparing your medication and supplies to setting up your pump and completing your infusion, our video guides you through the entire process to help you feel supported and informed every step of the way.

See the Transcript

IVIG and SCIG Therapy with Soleo Health

Patients with complex conditions deserve a seamless, supported, and personalized immunoglobulin (IG) therapy journey. At Soleo Health, we combine clinical expertise with compassionate care to ensure every patient receives the right therapy, in the right setting, with the support they need every step of the way.

How Soleo Health Supports IG Therapy for Patients

From referral through ongoing treatment, our team is dedicated to removing barriers and simplifying care:

  • Fast insurance verification and pre-authorization support to help accelerate therapy initiation
  • Dedicated Patient Ambassadors who guide patients through onboarding and serve as a consistent point of contact
  • Comprehensive clinical monitoring and care management to ensure safety, adherence, and optimal outcomes
  • Financial assistance navigation, including researching copay support programs and charitable foundations
  • Experienced clinical review nurses who advocate for patients through prior authorizations and appeals

Where Does Soleo Health Provide IVIG and SCIG Therapy?

Soleo Health delivers IG therapy in the setting that best fits each patient’s needs, lifestyle, and clinical requirements:

  • Home infusion, offering comfort, convenience, and independence
  • Ambulatory infusion suites (AIS), providing a safe, controlled environment with clinical oversight
  • Physician offices and alternate sites of care, coordinated to ensure continuity and flexibility

Our national network and expert care teams make it possible to deliver high-quality IG therapy wherever patients are most comfortable.

Contact Us to Learn More