Timothy Grass Allergy Shots: The Gold Standard for Grass SCIT
Timothy grass allergy shots (SCIT) are the evidence gold standard for all temperate grass pollen immunotherapy — FDA-standardized at 100,000 BAU/mL with more RCT data than any other grass. Phl p 1 and Phl p 5 together detect >95% of grass-allergic patients' IgE, so a single Timothy vial functionally treats the entire Pooideae sensitization. Plan for 3–5 years for durable benefit.
About Curex’s SCIT program
Curex’s at-home allergy shots (SCIT) are coming soon and focus on the most common environmental allergens:
- • Pollens — tree, grass, weed & ragweed
- • Pet dander — cat & dog
- • Dust mites
- • Molds — Alternaria & mold mix
Timothy Grassis covered here for general education and may not be part of Curex’s current treatment set. Join the waitlist and our care team will help confirm your options.
Timothy Grass Allergy Immunotherapy: How It Works
Allergy immunotherapy is the only long-term treatment that re-trains the immune system to stop overreacting to timothy grass — rather than just masking symptoms with antihistamines or steroids. By gradually exposing the body to controlled doses of timothy grass allergen, immunotherapy shifts the underlying allergic response and produces relief that often outlasts treatment by 7–10 years.
There are two evidence-based forms of timothy grass immunotherapy used today, both built on the same desensitization principle but delivered very differently.
of sustained relief after a complete immunotherapy course — the only allergy treatment with proven long-term effect after stopping.
Allergy Shots (SCIT)
Weekly injections of timothy grass extract in a clinic, escalating over 3–6 months until a maintenance dose is reached. Continued monthly for 3–5 years. Longest clinical track record for timothy grass allergy.
- Strongest evidence base for severe and polysensitized patients
- Covered by most insurance plans
- Requires 50–100+ in-person clinic visits across the full course
- Or at home with no clinic visits— Curex’s Virtual Shot Room model delivers the same SCIT program with live video supervision by trained Curex clinical staff for the first injection from each new vial or concentration and restarts after gaps or reactions.
Allergy Drops / Tablets (SLIT)
Daily drops or dissolvable tablets containing timothy grass extract, held under the tongue at home. Same desensitization principle, delivered without injections. WHO-recognized as an effective form of allergy immunotherapy since 2001.
- Taken at home — no weekly clinic trips, no needles
- Lower systemic reaction rate than allergy shots
- Curex offers prescription timothy grass immunotherapy drops with allergist oversight
The rest of this page goes deep on allergen-specific immunotherapy with shots — protocol, efficacy data, side effects, and cost. If you’d rather skip the clinic and treat timothy grass allergy with at-home drops, see how Curex sublingual immunotherapy compares below.
What is Timothy Grass?
The biology, taxonomy, and clinical fingerprint of Timothy Grass — the foundation of how SCIT targets it.
Phleum pratense inflorescence showing the distinctive cylindrical spike. Named after Timothy Hanson who promoted it in 1720s colonial America.
- Scientific name
- Phleum pratense
- Family
- PoaceaeGrass family
- Type
- Cool-season hay/pasture grass pollen
- Native to
- Europe and temperate Asia; naturalized throughout North America
- Allergen proteins
- Phl p 1 (major) — Group 1 beta-expansin, >90–95% sensitizationPhl p 2 (major) — Group 2 expansin-like, ~60% sensitizationPhl p 3 — Group 3 expansin-like, ~70% sensitizationPhl p 4 (major) — Group 4 berberine bridge enzyme, 54–92% sensitizationPhl p 5 (major) — Group 5 ribonuclease-like, 65–90% sensitization (Pooideae-restricted)Phl p 6 (major) — Group 6 Group 5-related, variable sensitizationPhl p 7 — Polcalcin, ~10% sensitization (pan-allergen)Phl p 11 — Ole e 1-like, 20–60% sensitizationPhl p 12 — Profilin, ~15–20% sensitization (pan-allergen)Phl p 13 — Polygalacturonase, ~50–56% sensitization
- Particle size
- 28–35 μm
- Avoidance difficulty
- Nearly impossible
How Timothy Grass Allergy Presents
Symptoms by body system — useful for distinguishing Timothy Grass sensitivity from overlapping allergies and infections.
Respiratory
- Profuse nasal discharge and congestion during May–July season
- Repeated sneezing triggered by outdoor exposure or hay-field proximity
- Asthma exacerbation — grass pollen is a documented asthma trigger
- Thunderstorm asthma risk when timothy pollen grains osmotically rupture in humidity
- Post-nasal drip and throat irritation persisting through June peak
Ocular
- Intense itching and redness of the conjunctiva during peak season
- Watery eye discharge triggered by outdoor exposure
- Eyelid swelling during high-count days
- Photophobia in severe allergic conjunctivitis
Dermal
- Contact urticaria from direct handling of timothy hay or fresh-cut grass
- Generalized pruritus during high-pollen days in severely sensitized patients
- Atopic dermatitis flares associated with peak grass pollen season
- Hives with direct grass contact in sensitive individuals
Systemic
- Profound fatigue during the June peak — 'allergy fog' from chronic histamine load
- Sleep disruption from persistent nasal congestion
- OAS (oral itching/tingling) from grass profilin (Phl p 12) cross-reacting with tomato, melon, celery, and peach
- Reduced quality of life and missed work days during season
A positive Phl p 5 IgE result is essentially a green light for single-species Timothy SCIT. Because Pooideae grasses share that Group 5 protein architecture at >90% sequence identity, there is no clinical advantage to mixing five different grass species when one Timothy vial will bind the patient's relevant IgE epitopes across the entire subfamily.
When & Where Timothy Grass Peaks
Allergen intensity by month and by state. Useful for timing SCIT start dates and travel planning.
12-Month Intensity
Peak: early June across the Northeast, Upper Midwest, and Pacific Northwest· Approximately 10–12 weeks of clinically significant exposure (May–July)
US Exposure Map
20 high-intensity statesExposure intensity by state (text version)
- ME:
- High
- VT:
- High
- NH:
- High
- WA:
- High
- MT:
- High
- ND:
- Moderate
- MN:
- High
- WI:
- High
- MI:
- High
- NY:
- High
- MA:
- High
- OR:
- High
- ID:
- High
- WY:
- Moderate
- SD:
- Moderate
- IA:
- High
- IL:
- High
- IN:
- High
- OH:
- High
- PA:
- High
- NJ:
- High
- CT:
- High
- RI:
- High
- CA:
- Moderate
- NV:
- Moderate
- UT:
- Moderate
- CO:
- Moderate
- NE:
- Moderate
- MO:
- Moderate
- KY:
- Moderate
- WV:
- Moderate
- VA:
- Moderate
- MD:
- Moderate
- DE:
- Moderate
- AZ:
- Low
- NM:
- Low
- KS:
- Moderate
- AR:
- Low
- TN:
- Low
- NC:
- Low
- SC:
- Low
- OK:
- Low
- LA:
- Low
- MS:
- Low
- AL:
- Low
- GA:
- Low
- TX:
- Low
- FL:
- Low
- AK:
- Low
- HI:
- Low
What Timothy Grass Cross-Reacts With
Patients sensitized to one allergen often react to others sharing similar proteins. This map shows the documented molecular overlaps.
Timothy grass is the 'Rosetta Stone' of Pooideae cross-reactivity — its 10 characterized WHO/IUIS allergens define the protein architecture shared across all temperate grasses, meaning a timothy-allergic patient is simultaneously sensitized to every grass in this subfamily.
Poa p 1 shares >90% sequence identity with Phl p 1; Group 5 homolog confirmed
Phl p 12 profilin cross-reacts with food profilins; OAS symptoms are heat-labile (cooking eliminates risk)
Grass Pollen–Food Cross-Reactivity Syndrome
Phl p 12 (profilin) cross-reacts with profilins in tomato, melon, celery, peach, and other raw foods, causing oral itching or tingling in up to 47–70% of grass-pollen-allergic patients. Symptoms are limited to the mouth and throat and resolve in minutes; cooking inactivates the profilin and eliminates the reaction.
Is SCIT Right for Your Timothy Grass Allergy?
Answer 5 questions to assess whether Timothy grass SCIT matches your allergy profile.
How severe are your grass pollen symptoms during the May–July season?
The Timothy Grass SCIT Protocol
Timothy SCIT uses the most standardized, well-characterized extract in grass immunotherapy — 100,000 BAU/mL FDA-standardized Phleum pratense extract — with a build-up schedule that has been refined across decades of clinical practice.
Your allergist will start with a highly diluted extract and progressively increase the concentration at each visit. The goal is to reach the maintenance dose without triggering a systemic reaction. Pre-seasonal initiation 4–6 months before the May peak allows full build-up before peak pollen counts. Cluster protocols (clinic-only — not available through Curex) can compress build-up to 4–8 weeks but require closer observation.
Once the target maintenance dose is reached, injections shift to a maintenance schedule individualized by your allergist. Each injection maintains immune tolerance built during the build-up phase. Per the AAAAI/ACAAI Practice Parameter (Cox et al. 2011), patients should remain on maintenance for at least 3 years to achieve durable benefit. A 30-minute post-injection observation period is required at every visit.
Durham et al. 2010 (JACI 125:131) demonstrated 2-year sustained clinical benefit after completing a 3-year Timothy immunotherapy course. Many patients maintain durable remission for years after discontinuation; your allergist will assess symptom status before stopping treatment.
Extract Concentration Ladder
You progress through each vial during build-up. Concentration increases ~10x per step.
What the Research Shows for Timothy Grass SCIT
Timothy grass SCIT has the most extensive RCT evidence base of any single grass allergen — the same extract that underlies both Grastek and Oralair SLIT tablets and has been evaluated across 51 controlled trials in the landmark Calderon Cochrane meta-analysis.
- Symptom-medication score reduction32%
- Standardized mean difference (symptoms)73%Calderon et al. 2007, Cochrane Database (SMD -0.73 across 51 grass SCIT trials)
- TCS reduction (SLIT tablet — Timothy Grastek/Grazax)25%Frew 2008, JACI 121:1234 — SQ Grass SLIT tablet >800 patients, Pooideae-equivalent
- Sustained benefit year 4 (post-3-yr course)70%Durham et al. 2010, JACI 125:131 — 2-yr sustained benefit after 3-yr Timothy immunotherapy
Across 51 controlled grass pollen SCIT trials (Calderon Cochrane 2007), the class effect for standardized Pooideae extracts — led by Timothy — is among the strongest in allergy immunotherapy. The 32% symptom-medication score reduction in Frew 2006 is conservative; observational data and real-world practice suggest higher reductions at full maintenance. The key clinical decision is committing to the full 3-year course to achieve durable benefit beyond the treatment period.
Ready to skip the surprise bills?
At-home allergy shots (SCIT) are designed by board-certified allergists. See the listed SCIT plan rate in our pricing record and request a quote for eligibility, initiation and total care costs.
- MD-ledBoard-certified allergists
- QuoteTotal care estimate
- 50K+Patients treated
- HSA/FSAEligible
Timothy Grass SCIT Side Effects
Timothy grass SCIT has an excellent long-term safety record, with the vast majority of reactions local and self-limiting. With Curex, that record is preserved at home through a USP <797> sterile-compounded serum, a Virtual Shot Room–supervised the first injection from each new vial or concentration, a prescribed epinephrine auto-injector confirmed on hand, and gradual week-by-week escalation under allergist oversight.
Local reactions
4 documented| Reaction | Rate | Severity |
|---|---|---|
Injection site swelling Expected response; swelling >3 cm may prompt dose adjustment at next visit | Rate 30–50% | Mild |
Injection site itching/redness Peaks 15–30 min post-injection; typically resolves within 2 hours | Rate 25–50% | Mild |
Large local reaction (>5 cm swelling) Prompts dose reduction at the next injection; not a contraindication to continuing SCIT | Rate 5–10% | Moderate |
Delayed local swelling (4–8 hrs post-injection) Common; apply cold compress and oral antihistamine as needed | Rate 5–15% | Mild |
Systemic reactions
4 documented| Reaction | Rate | Severity |
|---|---|---|
Generalized urticaria Requires dose reduction protocol; document and report to allergist | Rate 0.1–0.5% per injection | Moderate |
Rhinitis/conjunctivitis flare Treated with antihistamine; not a reason to stop SCIT | Rate 0.5–2% | Mild |
Asthma exacerbation (mild) Higher risk if asthma is poorly controlled on day of injection — always assess peak flow before injecting | Rate 0.1–0.3% | Moderate |
Anaphylaxis The 30-minute post-injection observation requirement exists specifically to detect and treat anaphylaxis immediately with epinephrine | Rate <0.001% per injection | Severe |
Systemic reactions, when they occur, typically begin within about 30 minutes of an injection. Bernstein et al. 2010 (J Allergy Clin Immunol) documented no SCIT fatalities in the US during the study period under proper protocols. Curex builds that safety margin into at-home care: the first injection from each new vial or concentration is supervised live in the Virtual Shot Room, a prescribed epinephrine auto-injector is confirmed on hand before the first injection, and a board-certified allergist oversees gradual dose escalation.
SCIT vs Alternatives for Timothy Grass
Timothy-allergic patients have four clinically proven options ranging from the longest-lasting disease modification (SCIT) to the quickest daily convenience (antihistamines).
| Criterion | At-Home SCIT (Curex)Best | SLIT tablets (Grastek/Oralair) | Avoidance | Medications |
|---|---|---|---|---|
| Effectiveness | High (32% improvement, Frew 2006) | Moderate–High (10–34% TCS reduction) | Low (pollen is airborne, inescapable) | Moderate (symptomatic relief only) |
| 5-yr cost estimate | $3,500–$15,000 | $3,000–$8,000 | Minimal | $500–$2,000/yr |
| Duration of benefit | 7–12 years | 2–3 years post-treatment | Only while avoiding | Only while taking |
| Convenience | At-home self-injection; same weekly build-up then monthly cadence | Daily at home | Very difficult outdoors | Daily pills/sprays |
| Safety | Excellent; Virtual Shot Room–supervised first dose + prescribed epi on hand | Very safe; black box warning first dose | Safe | Good; Singulair black box warning |
| Lasting effect after stopping | Yes — durable remission | Partial | No | No |
At-Home SCIT (Curex)Best
SLIT tablets (Grastek/Oralair)
Avoidance
Medications
SCIT is the only option proven to induce durable disease modification lasting years beyond treatment. Curex now delivers that same subcutaneous immunotherapy as an at-home allergy shot with pricing confirmed in a current program quote: a personalized Timothy/Pooideae serum compounded under USP <797>, with the first injection from each new vial or concentration supervised live in the Virtual Shot Room by trained Curex clinical staff, a prescribed epinephrine auto-injector confirmed on hand, and week-by-week dose escalation overseen by a board-certified allergist — so eligible patients get the durable-remission modality without weekly clinic trips.
What Timothy Grass SCIT Actually Costs
Most major commercial insurers cover timothy grass SCIT under standard allergy benefits when prescribed by a board-certified allergist. Out-of-pocket cost varies widely by deductible and co-insurance — patients should verify benefits before starting a 3–5 year course. Curex at-home IgE testing identifies specific timothy grass sensitization before allergist consultations, eliminating the need for an initial skin-test visit.
Cost range varies by deductible, co-insurance, and clinic.
Verify these codes with your insurer to confirm coverage.
See the listed Environmental Allergy Shots Plan rate, commercial terms dated 2026-10-12; consultations are included without copay. Confirm availability, eligibility, other included services, testing, any in-person care, insurance responsibility and billing cadence in your written quote before enrolling.
Join the waitlistStop guessing about your timothy grass allergy. Get a plan.
Take Curex’s 3-minute allergy quiz. A board-certified allergist will review your symptoms and recommend the right immunotherapy path for you — shots or drops.
Free quiz · Board-certified allergists · 50,000+ patients treated · HSA/FSA eligible
Timothy Grass SCIT — Frequently Asked
Quick answers to the questions patients ask most before starting treatment.
Most patients notice meaningful symptom improvement during their second or third grass season on Timothy SCIT — typically after completing the 3–6 month build-up phase and reaching maintenance. Some patients report partial improvement during their first season, but the full clinical benefit develops over 2–3 years of maintenance therapy. Per Calderon et al. 2007 (Cochrane), the standardized mean difference in symptoms across 51 grass SCIT trials was -0.73, indicating consistent clinically meaningful benefit across the course of treatment. Durham et al. 2010 (JACI 125:131) showed that benefit continued for at least 2 years after completing a 3-year course — meaning the investment compounds over time.
Because all temperate Pooideae grasses — including Kentucky bluegrass, orchard, perennial rye, fescue, sweet vernal, and redtop — share >90% sequence identity at the Phl p 1 Group 1 allergen and possess the same Group 5 (Phl p 5) protein family, a single Timothy SCIT vial clinically covers the entire temperate grass sensitization. This has been confirmed in component-resolved diagnostics research (Hauser et al. 2010, JACI) and endorsed by the AAAAI/ACAAI Practice Parameter (Cox et al. 2011). The one important exception is Bermuda grass (Cynodon dactylon), which belongs to a different subfamily (Chloridoideae) and completely lacks Group 5 allergens — Bermuda requires a separate vial if the patient is also sensitized to it.
Grastek is a timothy-only FDA-approved sublingual immunotherapy tablet (2800 BAU, ages 5–65), taken daily at home. Oralair is a 5-grass SLIT tablet (300 IR, ages 10–65) containing sweet vernal, orchard, perennial rye, Timothy, and Kentucky bluegrass. Timothy allergy shots (SCIT) involve weekly injections during build-up and ongoing maintenance injections. All three approaches use the same Phleum pratense or Pooideae-equivalent extract proteins. SCIT has the longest evidence base and may produce the most durable disease modification; traditionally it meant clinic visits, but Curex now offers it as an at-home shot with a USP <797> compounded serum, Virtual Shot Room–supervised the first injection from each new vial or concentration, and a prescribed epinephrine auto-injector confirmed on hand. A large safety study of self-administered allergen immunotherapy (Schaffer et al., 2015) found that across 23,614 patients giving 2,021,600 injections, the systemic reaction rate was just 0.16% per patient with no fatalities — lower than the 3%–14% typically seen with office-based shots. Both SLIT tablets are more convenient but must be taken daily and evidence for post-treatment durability is shorter-term. No head-to-head RCT has compared Grastek vs Oralair vs SCIT directly.
Yes — antihistamines are generally permitted on shot days and can actually reduce local reaction severity at the injection site. Your allergist may recommend taking a non-sedating antihistamine (cetirizine, loratadine, or fexofenadine) an hour before each injection during the build-up phase. There is one caveat: antihistamines can mask early symptoms of a systemic reaction, so watching for symptoms after each dose matters. With Curex, trained Curex clinical staff supervise the first injection from each new vial or concentration live in the Virtual Shot Room and confirm a prescribed epinephrine auto-injector is on hand, and the care team guides your same-day antihistamine protocol.
The protocol for missed doses depends on how long the gap was. A gap of 1–2 weeks during build-up usually means resuming at the same dose. A gap of 3–4 weeks may require stepping back one or two dilutions. A gap of more than 4 weeks often requires restarting further back in the build-up schedule, particularly if the patient has been off injections over the summer break. Your allergist will assess the gap duration, your current tolerance level, and pollen season timing before deciding how to resume. Never resume at full maintenance dose after a prolonged break without physician guidance.
Most major commercial insurance plans cover Timothy grass allergy shots under standard allergy benefits, since it is an FDA-standardized extract prescribed by a board-certified allergist for a medically documented condition. Coverage typically requires a prior authorization showing failed conservative therapy (medications). Common CPT codes billed are 95115 (single injection), 95117 (multiple allergen injection), and 95165 (extract preparation per dose unit). Out-of-pocket costs after insurance vary by plan deductible and co-insurance; many patients pay $30–$100 per visit. Medicare Part B covers allergy injections but not the extract preparation in some plans.
Yes — Timothy grass SCIT is well-established for children. AAAAI guidelines support starting allergen immunotherapy in children typically at age 5 and older. The build-up schedule is the same as for adults, and children often tolerate SCIT well with excellent long-term outcomes. Importantly, starting SCIT in childhood may prevent new sensitizations from developing — early intervention has been associated with reduced risk of progressing from allergic rhinitis to asthma. Both Grastek (SLIT tablet, ages 5–65) and Oralair (ages 10–65) are FDA-approved alternatives for pediatric patients who prefer not to have injections. Note that Curex's at-home pilot is currently open to patients age 12 and older; children under 12 should pursue SCIT through an in-clinic pediatric allergist. A board-certified pediatric allergist should confirm the diagnosis and supervise the course.
Thunderstorm asthma is a documented phenomenon where grass pollen grains — particularly Pooideae species including Timothy — absorb moisture during storms and osmotically rupture into sub-pollen particles 0.5–2.5 micrometers in diameter. These ultra-fine particles penetrate deep into the lower airways rather than depositing in the upper airway like whole pollen grains, triggering bronchospasm even in patients without prior asthma history. The most dramatic documented event was the Melbourne 2016 thunderstorm asthma episode — 10 deaths and ~10,000 emergency presentations linked primarily to Lolium perenne (perennial ryegrass). Timothy was also implicated in similar events (Marks et al. 2001, Wagga Wagga). SCIT or SLIT immunotherapy for grass pollen is protective: post-Melbourne 2016 analyses found 71% of immunotherapy-treated grass-allergic patients were asymptomatic during the event versus 24% of untreated patients.
This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider with questions about a medical condition. Content reviewed by board-certified allergists at Curex.
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