Allergy Shots vs. Allergy Drops vs. ILIT: Full Comparison
- Allergy shots (SCIT) mean regular in-clinic injections for three to five years.
- Allergy drops or tablets (SLIT) follow a similar multi-year timeline, often dosed at home after the first visit or two.
- ILIT, the fastest of the three to finish, delivers allergen into a lymph node, typically over a handful of visits across a few months.
- All three introduce allergen in small amounts so your immune system builds tolerance over time. They differ in method and timeline, not underlying approach.
- Many providers offer more than one option, so a single consultation can cover all three.
Choosing an allergy treatment usually comes down to three options: allergy shots (SCIT), allergy drops or tablets (SLIT), and intralymphatic immunotherapy (ILIT). All three work the same basic way: small, controlled amounts of an allergen train your immune system to build tolerance. Where they differ is delivery and time commitment.
Allergy Shots (SCIT)
Subcutaneous immunotherapy, better known as allergy shots, is the most established of the three options and has been used for decades. Treatment starts with weekly or biweekly injections under the skin, building up to a maintenance dose, then continues on a monthly schedule for three to five years. Each visit includes a short waiting period afterward so your allergist can monitor for a reaction.
Because it's the longest-standing option, SCIT is also the one insurers cover most often. That's not guaranteed for your specific plan, so it's worth a quick call to your insurer before committing to a multi-year course.
Allergy Drops & Tablets (SLIT)
Sublingual immunotherapy, or SLIT, means allergy drops or dissolving tablets placed under the tongue. It follows a similar multi-year timeline to SCIT, but without repeat injections. After an initial in-office visit or two, many SLIT formulations are taken at home, cutting down on clinic trips. Formulation and duration vary more with SLIT than with the other two options, since it depends on which specific allergen extract and dosing schedule your allergist prescribes.
Intralymphatic Immunotherapy (ILIT)
Intralymphatic immunotherapy takes a different approach. Instead of repeated injections under the skin over several years, ILIT delivers allergen extract directly into a lymph node, guided by ultrasound, typically in a handful of visits over a matter of months. It's newer than SCIT and SLIT, so it's generally self-pay rather than insurance-covered today. It's also built around a defined set of common allergens. A broader or more complex allergy profile may be better suited to SCIT or SLIT instead.
Side by Side
| ILIT | SCIT (Allergy Shots) | SLIT (Allergy Drops/Tablets) | Allergy Medicine | |
|---|---|---|---|---|
| What it targets | The underlying allergy | The underlying allergy | The underlying allergy | Symptoms |
| Treatment timeframe | A few months | 3 to 5 years | 3 years or more | Daily or as needed, indefinitely |
| Administration | Lymph node injection | Under-skin injection | Under-tongue drops or tablets | Pills, sprays, or eye drops, over the counter or by prescription |
| Typical visit frequency | Typically 3 visits, about a month apart | 1 to 2 visits weekly for 3 to 6 months, then monthly | Daily doses at home, plus periodic office visits | None for over-the-counter options, checkups for prescriptions |
Which Is Right for You?
There's no universally best option. SCIT, SLIT, and ILIT are all valid approaches to allergy immunotherapy. Which one fits depends mostly on two things: how you feel about needles versus a longer at-home routine, and what your insurance actually covers. Many allergists who offer ILIT also offer SCIT and/or SLIT, so a single consultation can usually cover all three.
Ready to talk to a provider about your options? Find an ILIT provider near you who can walk you through what fits your situation.
Frequently Asked Questions
Allergy shots (SCIT) are injected under the skin at a clinic on a regular schedule for several years. Allergy drops or tablets (SLIT) go under the tongue instead, often self-administered at home after the first visit or two, over a similarly multi-year course. Both work the same underlying way: small amounts of allergen train your immune system to build tolerance. The real difference is where treatment happens, a clinic versus your own kitchen counter.
Yes, in how long the course takes. Intralymphatic immunotherapy (ILIT) goes into a lymph node under ultrasound guidance, not under the skin or under the tongue. That's the whole reason a typical ILIT course fits into a handful of visits over months, while SCIT and SLIT run for years.
Coverage varies by plan and by treatment. SCIT has the longest track record, so it's the option insurers cover most consistently. ILIT is newer and typically self-pay right now. That could change as more insurers add coverage, so it's worth asking your specific plan rather than assuming based on either treatment's current status.
Many allergists who offer ILIT also offer SCIT and SLIT, so combining or switching between them is possible in practice, not just in theory. What decides it is your own case: which allergens you're being treated for and how far into a current course you already are. That's specific enough that it has to be a real conversation with your provider, not a general rule this page can give you.
There's no single factor that decides it. A consultation with an allergist who offers all three treatments is the most direct path: they can review your actual allergy test results and talk through which approach fits how you live, not just which one exists as an option.
