Updated: January 11, 2026

What Is Onyda XR? Uses, Dosage, and What You Need to Know in 2026

Author

Peter Daggett

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What Is Onyda XR?
What Is Onyda XR Used For?
Why Is Onyda XR Unique?
How to Take Onyda XR: Dosing Instructions
What Does Onyda XR Treat in ADHD?
Who Should NOT Take Onyda XR?

A complete guide to Onyda XR (clonidine) — what it is, what it treats, how to take it, and everything parents and patients need to know in 2026.

Onyda XR is a prescription medication approved by the FDA in May 2024 for the treatment of attention-deficit/hyperactivity disorder (ADHD) in children aged 6 and older. It's the first — and so far only — liquid non-stimulant ADHD medication approved in the United States.

If your child's doctor has just prescribed Onyda XR or is considering it, this guide answers the most important questions: what is it, how does it work, how do you take it, and what should you watch for?

What Is Onyda XR?

Onyda XR is the brand name for clonidine hydrochloride extended-release oral suspension. It contains 0.1 mg of clonidine per mL and is an orange-flavored liquid taken once daily at bedtime.

Key facts at a glance:

Generic name: Clonidine hydrochloride

Manufacturer: Tris Pharma, Inc.

FDA approved: May 24, 2024

Drug class: Centrally acting alpha-2 adrenergic agonist

Controlled substance: No — not a DEA-scheduled substance

Formulation: Extended-release oral suspension, 0.1 mg/mL, orange-flavored

Generic available: No

What Is Onyda XR Used For?

Onyda XR is FDA-approved for the treatment of ADHD as:

Monotherapy: As the sole ADHD treatment for children who cannot or should not use stimulant medications

Adjunctive therapy: Added to a stimulant medication (like Adderall or Ritalin) when the stimulant alone doesn't fully control symptoms

It is approved for children aged 6 and older. It is not approved for children under 6 or for adults (though off-label adult use does occur under physician guidance).

Why Is Onyda XR Unique?

Before Onyda XR, there were no extended-release liquid ADHD medications that were non-stimulant. This matters for several reasons:

Children who can't swallow pills now have a non-stimulant liquid option

Nighttime dosing may improve morning ADHD symptom control while reducing daytime sedation

Not subject to DEA Schedule II production limits that contribute to stimulant shortages

How to Take Onyda XR: Dosing Instructions

Starting dose: 0.1 mg (1 mL) once daily at bedtime

Titration: Dose may be increased by 0.1 mg per day at weekly intervals based on response

Maximum dose: 0.4 mg (4 mL) once daily at bedtime

Food: Can be taken with or without food

Administration: Shake bottle gently. Use the oral dosing syringe provided. Child should be seated with head slightly tilted back; place syringe into cheek, push plunger slowly.

Storage: Room temperature 68–77°F. Discard unused portion 30 days after opening (30 mL/60 mL) or 60 days (120 mL).

What Does Onyda XR Treat in ADHD?

In clinical studies (two 8-week, placebo-controlled trials and one 40-week randomized withdrawal study involving children aged 6–17), Onyda XR significantly improved:

Hyperactive and impulsive behavior

Inattention

Overall ADHD symptom scores (ADHD-RS-IV) starting at week 5 versus placebo

Who Should NOT Take Onyda XR?

Children under 6 years old

Patients with a known allergy to clonidine

Patients with severe heart conditions (bradycardia, AV block) without close monitoring

Patients taking other CNS depressants or cardiac conduction-affecting drugs (without close monitoring)

For a full review of side effects and warnings, see: Onyda XR Side Effects: What to Expect and When to Call Your Doctor.

Once you have your prescription, medfinder can help you find a pharmacy near you with Onyda XR in stock.

Frequently Asked Questions

Onyda XR (clonidine hydrochloride extended-release oral suspension) is FDA-approved to treat ADHD in children aged 6 and older. It can be used alone (monotherapy) or added to a stimulant medication. It is the first and only liquid non-stimulant ADHD medication approved in the United States.

Yes. Onyda XR contains clonidine hydrochloride as its active ingredient. However, it is a unique formulation — an extended-release oral suspension using Tris Pharma's LiquiXR® technology — that provides once-daily dosing and a different pharmacokinetic profile than other clonidine products like Kapvay tablets. They are not interchangeable mg-for-mg.

In clinical studies, significant improvement in ADHD symptoms (measured by ADHD-RS-IV scores) was observed at week 5. Some patients may notice early effects within 1–2 weeks, but full benefit typically emerges after 4–6 weeks of treatment at the appropriate dose.

Both contain clonidine, but Onyda XR is an extended-release oral suspension (liquid) taken once daily at bedtime, while Kapvay is an extended-release tablet taken twice daily. They have different pharmacokinetic profiles — Onyda XR's steady-state trough concentration is about 26% lower than equivalent-dose Kapvay. They cannot be substituted mg-for-mg.

Onyda XR is FDA-approved only for ADHD. However, clonidine in other formulations is used for hypertension, tic disorders, opioid withdrawal, and anxiety. Off-label use of Onyda XR for other conditions may occur under physician supervision but is not FDA-approved for those uses.

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