Allergy Drops vs. Allergy Shots: Which Is Right for You?

What does allergen immunotherapy actually do?

Both allergy shots and sublingual immunotherapy gradually expose the immune system to increasing amounts of the allergen it overreacts to. Over time, this exposure shifts the immune response from reactive to tolerant — reducing the severity of symptoms during everyday exposure. This is the only class of treatment for allergic rhinitis, allergic asthma, or stinging-insect allergy that modifies the underlying disease rather than just treating symptoms 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing..

A typical course of immunotherapy lasts three to five years, and benefits often persist for years after the course ends.

How do allergy shots (SCIT) work?

Allergy shots (subcutaneous immunotherapy, SCIT) are injections under the skin of the upper arm:

Build-up phase: Injections one to two times per week with gradually increasing allergen doses over roughly three to six months.

Maintenance phase: Once the therapeutic dose is reached, injections continue monthly for three to five years.

After each injection: You wait 20–30 minutes in the clinic because systemic reactions, though uncommon, can occur and require immediate treatment 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing..

Shots are administered exclusively in a medical setting — they cannot be taken at home. This requires frequent clinic visits but ensures immediate access to emergency care if needed.

SCIT can treat a broad range of allergens in a single treatment regimen: tree, grass, and weed pollens; dust mites; cat and dog dander; mold; and stinging insects (SCIT is the standard of care for venom allergy).

How does sublingual immunotherapy (SLIT) work?

Sublingual immunotherapy places allergen extract under the tongue, where it is absorbed through the mouth's mucosal lining:

FDA-approved tablets are available for specific allergens with well-established efficacy and age ranges 3Ref 3Blaiss M, DuBuske L, Nolte H, Opstrup M, Rance K (2023).A practical guide to prescribing sublingual immunotherapy tablets in North America for pediatric allergic rhinoconjunctivitis.FDA-approved SLIT tablet products (Grastek, Oralair, Ragwitek, Odactra, Itulatek), approved allergens, approved age ranges (5–65 for pollens; 12–65 for dust mite); first-dose clinic observation then home administration.: - *Grastek* (Timothy grass) — ages 5–65 - *Oralair* (5-grass mixture) — ages 5–65 - *Ragwitek* (short ragweed) — ages 5–65 - *Odactra* (house dust mite) — ages 12–65 - *Itulatek* (birch tree pollen) — ages 18–65

Off-label liquid drops are compounded formulations used by some allergists, targeting your specific allergy panel based on testing.

The first dose is given in the clinic with 30 minutes of observation. Subsequent doses are taken at home daily — the primary convenience advantage of SLIT over shots. Like shots, treatment typically continues for three to five years 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing.2Ref 2Bousquet J, Schünemann HJ, Togias A, Bachert C, Erhola M, Hellings PW, et al. (2020).Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence.Immunotherapy as the only disease-modifying treatment for allergic rhinitis; SLIT evidence base and GRADE-supported place in management; venom allergy treated with SCIT not SLIT; insurance and coverage considerations..

How do they compare on safety?

Allergy shots (SCIT) carry a small but real risk of systemic allergic reactions including anaphylaxis — the reason 20–30 minutes of clinic observation is required after each injection. The overall risk is low but is why shots cannot be given at home 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing..

Sublingual immunotherapy (SLIT) has a more favorable systemic safety profile. The most common side effects are local — itching or tingling in the mouth or throat, especially when starting. Systemic reactions are reported but are substantially less common than with SCIT, which is why home administration is permitted after the initial supervised dose 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing.2Ref 2Bousquet J, Schünemann HJ, Togias A, Bachert C, Erhola M, Hellings PW, et al. (2020).Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence.Immunotherapy as the only disease-modifying treatment for allergic rhinitis; SLIT evidence base and GRADE-supported place in management; venom allergy treated with SCIT not SLIT; insurance and coverage considerations..

Both methods require an epinephrine auto-injector to be accessible: for SCIT while at home between visits, and for SLIT in the event of an unexpected systemic reaction at home.

Which allergens can each form treat?

Allergy shots (SCIT) can address a broad range of allergens in a single regimen — particularly valuable for people with multiple sensitivities. SCIT is the standard of care for stinging insect (venom) allergy; sublingual immunotherapy is not used for venom 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing.2Ref 2Bousquet J, Schünemann HJ, Togias A, Bachert C, Erhola M, Hellings PW, et al. (2020).Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence.Immunotherapy as the only disease-modifying treatment for allergic rhinitis; SLIT evidence base and GRADE-supported place in management; venom allergy treated with SCIT not SLIT; insurance and coverage considerations..

Sublingual products (SLIT) are more limited. FDA-approved tablets cover specific pollens and dust mites 3Ref 3Blaiss M, DuBuske L, Nolte H, Opstrup M, Rance K (2023).A practical guide to prescribing sublingual immunotherapy tablets in North America for pediatric allergic rhinoconjunctivitis.FDA-approved SLIT tablet products (Grastek, Oralair, Ragwitek, Odactra, Itulatek), approved allergens, approved age ranges (5–65 for pollens; 12–65 for dust mite); first-dose clinic observation then home administration.. Off-label compounded liquid drops can target multiple allergens but have less regulatory oversight. Venom allergy cannot be treated sublingually.

Which is more convenient, and how do they differ on cost?

Sublingual therapy has a clear convenience advantage: home daily dosing eliminates repeated clinic visits required by shots (initially one to two per week). This is important for patients with demanding schedules, pediatric patients, and those who live far from an allergy clinic 1Ref 1Gurgel RK, Baroody FM, Damask CC, Mims JW, Ishman SL, et al. (2024).Clinical Practice Guideline: Immunotherapy for Inhalant Allergy.SCIT and SLIT both endorsed as immunotherapy modalities; patient education about differences in risks, benefits, convenience, and costs; observation period requirements; pre/co-seasonal SLIT dosing..

Insurance coverage: SCIT is widely covered by insurance as an established, guideline-recommended treatment. FDA-approved SLIT tablets are prescription products and covered by many plans, though coverage varies significantly. Off-label compounded liquid SLIT is frequently not covered. Checking your specific plan's formulary before starting either form is important 2Ref 2Bousquet J, Schünemann HJ, Togias A, Bachert C, Erhola M, Hellings PW, et al. (2020).Next-generation Allergic Rhinitis and Its Impact on Asthma (ARIA) guidelines for allergic rhinitis based on Grading of Recommendations Assessment, Development and Evaluation (GRADE) and real-world evidence.Immunotherapy as the only disease-modifying treatment for allergic rhinitis; SLIT evidence base and GRADE-supported place in management; venom allergy treated with SCIT not SLIT; insurance and coverage considerations..

Duration: Both approaches typically require three to five years for sustained benefit. Stopping early carries a risk of symptom relapse.