Are allergy drops FDA approved — and does it matter?

The short answer is: it depends on which allergy drops you mean.

FDA-approved SLIT tablets (yes, fully approved):
Four sublingual immunotherapy tablets have passed full FDA review with large clinical trials, standardized dosing, and post-marketing surveillance requirements. Oralair was the first, approved April 1, 2014 — the FDA stated it "provides an alternative to allergy shots that must be given in a health care provider's office." All four are prescription drugs available through any pharmacy.

Custom compounded SLIT drops (off-label, not individually FDA-reviewed):
The drops sold by telehealth providers are NOT FDA-approved products. They are custom formulations created by compounding pharmacies using FDA-approved allergen extracts — the same extracts that have been FDA-approved for allergy shots since the 1970s. The FDA's Center for Biologics Evaluation and Research (CBER) regulates these extracts. What's off-label is the delivery route: sublingual (under the tongue) instead of subcutaneous (injected under the skin).

This distinction matters: the active ingredients are regulated, but the specific formulation, concentration, and multi-allergen combinations in custom drops have not been individually reviewed by the FDA. No FDA warning letters or guidance documents have been issued prohibiting the practice of compounding SLIT drops from FDA-approved extracts. The enforcement actions that do exist (such as Curex's 2021 untitled letter, discussed below) have addressed promotional claims, not the legality or safety of compounded SLIT products themselves.

"Allergy drops" that are NOT immunotherapy:
Some companies sell homeopathic or supplement-based "allergy drops" that contain no standardized allergen extracts. These are a completely different product category and should not be confused with physician-prescribed SLIT.

Off-label prescribing occurs when a physician uses an FDA-approved medication for a purpose, population, or route not specified on the FDA label. It does not mean the use is illegal, experimental, or unsupported by evidence.

Examples of routine off-label prescribing in other specialties:
- Aspirin for heart attack prevention (approved for pain/fever)
- Gabapentin for neuropathic pain (approved for seizures)
- Trazodone for insomnia (approved for depression)
- Metformin for PCOS (approved for Type 2 diabetes)

The key difference with SLIT drops: while many off-label uses eventually receive FDA approval through supplemental applications, the path for custom compounded drops is structurally different. Each custom formulation is unique to the patient, making traditional clinical trials (which test a single standardized product) logistically impractical. This is why FDA-approved SLIT tablets exist for single allergens with standardized doses, but FDA-approved custom drops likely never will.

The AAAAI/ACAAI 2017 Practice Parameter (Greenhawt et al., PMID: 28284533) reflects this tension: the societies do not endorse off-label SLIT drops, but they acknowledge the practice exists and provide no mechanism to stop licensed physicians from prescribing them.

The US is an outlier in restricting SLIT to tablets. In Europe, both SLIT drops and tablets are marketed with regulatory authorization:

- Germany, France, Italy, Spain: Multiple liquid SLIT drop products hold national marketing authorizations, including Staloral (Stallergenes Greer) for multiple allergens
- EU-wide: Five SLIT tablets are EMA-approved: Grazax (grass, 2006), Oralair (5-grass, 2008), Acarizax/Odactra (HDM, 2015), Ragwizax (ragweed, 2017), and Itulazax (birch, 2019) — one more than the US
- Key difference: Europe authorizes both routes; the US mandates epinephrine auto-injector prescriptions for all SLIT-tablet patients (boxed warning), which Europe does not routinely require

This regulatory gap means US patients choosing custom drops are using a treatment format that has formal marketing authorization in major European markets but remains off-label domestically (Mahler et al. 2019, PMID: 30850069).

Curex has received two FDA communications — neither concerning the safety of allergy drops or patient harm — but both worth understanding:

March 2021 — CBER Untitled Letter: The FDA's Center for Biologics Evaluation and Research sent Curex an untitled letter regarding marketing claims about allergenic extracts. Untitled letters are the lower tier of FDA enforcement (below warning letters) and address promotional/labeling concerns, not safety issues.

September 2025 — CDER Warning Letter: The FDA's Center for Drug Evaluation and Research sent a warning letter about Curex's compounded semaglutide/tirzepatide (GLP-1 weight loss) products — a completely separate product line from allergy treatment. The September 2025 letter concerned a separate product line (GLP-1 weight management) and is unrelated to allergy treatment.

For context: Wyndly, Nectar, Quello, and HeyAllergy have no publicly identified FDA enforcement actions. The 2021 letter is more relevant to allergy patients (it concerned allergen marketing), while the 2025 letter concerned a different business vertical entirely.

Save your money on custom drops and choose an FDA-approved tablet instead if:

Your primary allergy is grass, ragweed, or dust mite only. FDA-approved tablets have standardized dosing from large pivotal trials, pharmacy benefit coverage ($15-25/month with copay cards), and the regulatory backing that custom drops lack. If you're mono-allergic to one of these three categories, the tablet is the stronger evidence-based choice.

Your allergist specifically objects to off-label SLIT on clinical grounds. If your doctor says "I don't prescribe drops because the evidence for multi-allergen compounded formulations is weak" — that's a legitimate clinical concern supported by the AAAAI position. If they say "drops aren't FDA-approved" without nuance — that's an incomplete answer.

You're uncomfortable with off-label prescribing in general. This is a valid personal preference. FDA approval provides a defined safety and efficacy standard that off-label use, by definition, has not met for that specific indication.

You don't need to avoid immunotherapy entirely just because custom drops are off-label. The extracts are FDA-approved, the prescribing physician is licensed, the compounding pharmacy is regulated, and the Cochrane Database confirms SLIT efficacy across 60 RCTs. "Off-label" is not the same as "unproven" — but it is different from "FDA-reviewed for this specific use."