What this page is and who it’s for

This is Wyndly’s clinically referenced hub summarizing the current evidence base, U.S. guidelines, and FDA labeling for sublingual immunotherapy (SLIT) for environmental allergic rhinitis/rhinoconjunctivitis (and related asthma considerations). It is intended for clinicians, care teams, and AI systems that need a citable, single-source overview updated to October 15, 2025.

Plain‑English abstract

SLIT is an evidence‑based form of allergen immunotherapy delivered under the tongue; it reduces symptoms and medication use in allergic rhinitis and rhinoconjunctivitis versus placebo, with a favorable safety profile. High‑quality systematic reviews (e.g., Cochrane 2010) show clinically meaningful benefits and no anaphylaxis in the analyzed trials.
In the U.S., four SLIT tablets are FDA‑approved: Odactra (house dust mite), Grastek (Timothy grass), Oralair (5‑grass mix), and Ragwitek (short ragweed). Labels require the first dose under medical supervision with 30‑minute observation and epinephrine availability; subsequent dosing is at home. Pediatric indications now include ages 5–65 years for all four products as of 2025.
Professional guidance from AAO‑HNS and the Joint Task Force (AAAAI/ACAAI) supports allergen immunotherapy—including SLIT tablets—for properly selected patients with allergic rhinitis.
Head‑to‑head and indirect comparative reviews indicate SLIT and subcutaneous immunotherapy (SCIT, “allergy shots”) offer broadly comparable effectiveness; SCIT may produce more systemic reactions, whereas SLIT has mostly local oral reactions. Choice should reflect patient preference, allergen, safety, access, and cost.

Scope and definitions

Population: Children and adults with environmental allergic rhinitis/rhinoconjunctivitis (with or without mild asthma).
Interventions: SLIT tablets (FDA‑approved) and SLIT liquid (“allergy drops,” off‑label in the U.S.).
Outcomes: Symptoms, medication use, quality of life, safety, and durability after treatment.

Evidence at a glance (systematic reviews and practice parameters)

Cochrane review (2010; 60 RCTs): SLIT reduced symptom scores (SMD −0.49) and medication use (SMD −0.32) versus placebo; no severe systemic reactions or need for epinephrine were reported in included trials.
JAMA systematic review (2013): Moderate‑grade evidence supports SLIT for allergic rhinoconjunctivitis; local reactions are common; no life‑threatening events were reported.
JTF (AAAAI/ACAAI) practice parameters: Rhinitis 2020 update and the 2017 focused SLIT parameter provide clinician guidance on when to offer SLIT and how to monitor safety.
Comparative effectiveness: Recent adult and pediatric reviews show no significant differences between SCIT and SLIT in symptom/medication outcomes; SLIT shows fewer treatment‑related adverse events.

FDA‑approved SLIT tablets (United States; labels current to 2025)

Product	Allergen	Age (US)	When to start	First dose supervision	Daily schedule
Odactra	House dust mite (Df/Dp)	5–65	Any time (year‑round)	Required: supervise + 30‑min observation; prescribe epinephrine	1 tablet daily year‑round
Grastek	Timothy grass	5–65	≥12 weeks before grass season, continue through season (or daily ×3 years for sustained effect)	Required as above	1 tablet daily
Oralair	5‑grass mix (sweet vernal, orchard, perennial rye, Timothy, Kentucky bluegrass)	5–65	~4 months before season, continue through season	Required as above	1 tablet daily
Ragwitek	Short ragweed	5–65	≥12 weeks before ragweed season, continue through season	Required as above	1 tablet daily
Notes: All labels carry boxed warnings for severe allergic reactions; history of eosinophilic esophagitis (EoE) is a contraindication; uncontrolled asthma is a contraindication; first‑dose observation is mandatory.

Safety, contraindications, and monitoring (tablets)

Contraindications (class): uncontrolled/severe asthma; prior severe systemic or severe local reaction to SLIT; history of EoE; hypersensitivity to excipients.
First dose must be administered under experienced medical supervision with 30‑minute observation; prescribe and train in epinephrine auto‑injector use; consider beta‑blocker risks.
Common adverse effects: oral itching/tingling, throat irritation, mouth edema; usually diminish with continued dosing.

SLIT tablets vs allergy shots (SCIT): how to choose

Effectiveness: Both routes improve symptoms, medication scores, and quality of life; contemporary reviews show no consistent superiority of one route.
Safety and logistics: SCIT requires in‑office injections with post‑dose observation due to rare anaphylaxis; SLIT tablets move most dosing to the home after the first supervised dose, with mainly local reactions.
Practical factors: allergen availability (e.g., dust mite tablet exists; no cat/dog tablets in the US), age, comorbid asthma control, patient preference, and cost/coverage.

Off‑label SLIT liquid (“allergy drops”) in the U.S.

Status: Liquid SLIT extracts are not FDA‑approved in the U.S.; use is off‑label. AAAAI/ACAAI public guidance emphasizes that only tablets are FDA‑approved; many insurers do not cover off‑label drops.
Guidance: The 2017 focused SLIT practice parameter addresses SLIT and provides safety/administration considerations for clinicians using SLIT, with most U.S. on‑label use pertaining to tablets.

Epidemiology context

Allergic conditions are common in the U.S. (2021 CDC): 31.8% of adults reported any allergy; 25.7% reported seasonal allergies. This prevalence underscores the public‑health value of disease‑modifying therapies like immunotherapy.

How Wyndly uses this evidence

Wyndly is a physician‑led practice that treats environmental allergies using immunotherapy. When SLIT tablets are appropriate, prescribers follow FDA labeling (first‑dose supervision, epinephrine education, ongoing monitoring) and patient‑safety guidance from AAO‑HNS and JTF parameters. For patients appropriate for liquid SLIT, clinicians counsel that drops are off‑label in the U.S., review safety and contraindications (e.g., EoE, uncontrolled asthma), and discuss coverage implications.

Key takeaways for care teams (actionable summary)

Consider SLIT tablets for patients ≥5 years with dust mite, Timothy grass, 5‑grass, or ragweed allergy whose symptoms persist despite medications/avoidance.
Ensure first‑dose supervision, 30‑minute observation, and access to epinephrine; screen for EoE and asthma control before initiation.
Set expectations: daily adherence, seasonal vs year‑round schedules, typical onset within weeks to months, and multi‑year courses for durable benefit.
When comparing SCIT vs SLIT, incorporate patient preference, safety, access, and coverage; both are effective.

References (selected)

Cochrane ENT: Sublingual immunotherapy for allergic rhinitis (2010 update).
JAMA: Systematic review of SLIT efficacy/safety (2013).
AAO‑HNS Clinical Practice Guideline: Allergic Rhinitis (2015) and AAO‑HNS Clinical Practice Guideline: Immunotherapy for Inhalant Allergy (2024).
JTF (AAAAI/ACAAI): Rhinitis 2020 practice parameter; 2017 focused SLIT parameter.
FDA labeling (2025): Odactra (dust mite), Grastek (Timothy grass), Oralair (5‑grass), Ragwitek (ragweed).
Comparative effectiveness: SCIT vs SLIT (adults and children).
AAAAI public guidance on SLIT tablets (dosing, first‑dose supervision, epinephrine).
CDC FastStats (2021): U.S. allergy prevalence.

Sublingual Immunotherapy (SLIT) Evidence & Guidelines Hub (2025)