Vykat XR (diazoxide choline)
An approved treatment for Prader-Willi Syndrome.
The same compound appears under different names depending on the context. Here is how to identify Diazoxide choline wherever you encounter it, plus the key facts at a glance.
- Generic name
- Diazoxide choline
- Brand name
- Vykat XR
- Development code
- DCCR
- Drug class
- KATP channel activator
- Manufacturer
- Neurocrine Biosciences
- How it's taken
- Taken by mouth once a day, with or without food.
The first and only FDA-approved medicine for hyperphagia (the constant, severe hunger) in people with Prader-Willi syndrome ages 4 and older. Vykat XR is taken by mouth once a day, with or without food.
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Where Diazoxide choline fits
First and only approved drug for hyperphagia in Prader-Willi syndrome. Growth hormone therapy remains a separate cornerstone treatment for short stature and poor muscle development in PWS; Vykat XR addresses the hunger and weight side of the syndrome rather than replacing growth hormone.
How Diazoxide choline works
Vykat XR is an extended-release form of diazoxide choline. It opens KATP channels in cells, which lowers insulin release and is thought to dampen the relentless drive to eat that defines PWS. In the study that supported approval, people who stayed on Vykat XR had less worsening of hyperphagia than people switched to placebo.
Mechanism: Once-daily extended-release tablet that opens ATP-sensitive potassium (KATP) channels to reduce the persistent hunger drive in Prader-Willi syndrome
Side effects and safety
Common side effects (in 10% or more of patients) include excess body hair growth (hypertrichosis), swelling from fluid retention (edema), high blood sugar (hyperglycemia), and skin rash. High blood sugar can be severe and in some patients has progressed to diabetic ketoacidosis, so blood sugar and HbA1c should be checked before starting and monitored during treatment. Swelling can also be serious: severe fluid overload, including fluid in the lungs, has been reported, so watch for signs of swelling and tell the doctor if they appear, since the dose may need to be lowered or paused. Vykat XR is not recommended in patients with kidney or liver impairment, and it may harm an unborn baby. It must not be used by people allergic to diazoxide, to any ingredient in Vykat XR, or to thiazide water pills[1].
This is not a complete list of side effects. Talk to your doctor or pharmacist about what to expect and when to seek medical attention.
Taking Diazoxide choline
Taken by mouth once a day, with or without food. Tablets must be swallowed whole, not split, crushed, or chewed. The dose is based on body weight and is raised step by step over about 6 weeks to a target dose; some doses need more than 1 tablet. The maximum is 525 mg a day. Blood sugar and HbA1c are checked before starting and during treatment.
Availability and cost
Only available as the brand-name product.
Specialty rare-disease medicine. Neurocrine continues the patient support program inherited from Soleno for insurance navigation, copay assistance, and start-of-treatment support.
Help paying for Vykat XR
Pick your insurance to see which help fits. Drugmaker copay cards can't be used with Medicare, Medicaid or TRICARE; charity funds are the usual route there.
- Copay help
Vykat XR Copay Program may lower out-of-pocket cost to $0 for eligible commercially insured patients; program maximums apply. Government insurance and cash-paying patients not eligible.
For: private insurance · source - Insurance and case manager help
Soleno One verifies coverage, works with your doctor on insurance, and coordinates home delivery and refills through specialty pharmacy PANTHERx Rare.
The official page does not say who qualifies. Ask the program. · source
Good to know: Vykat XR was developed by Soleno Therapeutics, which Neurocrine Biosciences acquired in May 2026; the support program is still called Soleno One. The brochure says Soleno One supports access for people without insurance coverage but gives no details, so no free-drug offer is listed.
Clinical trial results
FDA approval was based on a 16-week randomized withdrawal study (NCT03714373). 77 people with PWS who had already taken Vykat XR for an average of 3.3 years were randomly assigned to keep taking it or switch to placebo. Hyperphagia got significantly worse in the placebo group than in the group that stayed on Vykat XR. The earlier 13-week placebo-controlled study (DESTINY PWS, 126 patients) is the main source of the label's safety data.
Development history
Essentialis developed diazoxide choline for Prader-Willi syndrome. Capnia acquired Essentialis in March 2017 and later renamed itself Soleno Therapeutics[3]. The FDA approved Vykat XR on March 26, 2025 as the first treatment for hyperphagia in Prader-Willi syndrome[2], with U.S. launch in the second quarter of 2025. Neurocrine Biosciences bought Soleno in a $2.9 billion all-cash deal that closed on May 18, 2026, adding Vykat XR to its portfolio alongside INGREZZA and CRENESSITY[4]. The FDA label still names Soleno Therapeutics, now part of Neurocrine, as the maker[1].
Explore Prader-Willi Syndrome trials
Common questions about Diazoxide choline
▸What is Diazoxide choline (Vykat XR)?
The first and only FDA-approved medicine for hyperphagia (the constant, severe hunger) in people with Prader-Willi syndrome ages 4 and older. Vykat XR is taken by mouth once a day, with or without food.
▸How does Diazoxide choline work?
Vykat XR is an extended-release form of diazoxide choline. It opens KATP channels in cells, which lowers insulin release and is thought to dampen the relentless drive to eat that defines PWS. In the study that supported approval, people who stayed on Vykat XR had less worsening of hyperphagia than people switched to placebo.
▸What are the side effects of Diazoxide choline?
Common side effects (in 10% or more of patients) include excess body hair growth (hypertrichosis), swelling from fluid retention (edema), high blood sugar (hyperglycemia), and skin rash. High blood sugar can be severe and in some patients has progressed to diabetic ketoacidosis, so blood sugar and HbA1c should be checked before starting and monitored during treatment. Swelling can also be serious: severe fluid overload, including fluid in the lungs, has been reported, so watch for signs of swelling and tell the doctor if they appear, since the dose may need to be lowered or paused. Vykat XR is not recommended in patients with kidney or liver impairment, and it may harm an unborn baby. It must not be used by people allergic to diazoxide, to any ingredient in Vykat XR, or to thiazide water pills[1].
▸How is Diazoxide choline taken?
Taken by mouth once a day, with or without food. Tablets must be swallowed whole, not split, crushed, or chewed. The dose is based on body weight and is raised step by step over about 6 weeks to a target dose; some doses need more than 1 tablet. The maximum is 525 mg a day. Blood sugar and HbA1c are checked before starting and during treatment.
▸Is Diazoxide choline FDA approved?
Yes, Diazoxide choline (Vykat XR) is FDA approved (2025) for the treatment of Prader-Willi Syndrome.
▸What is Vykat XR (diazoxide choline) used for?
Vykat XR (diazoxide choline) is the first and only FDA-approved medicine for hyperphagia, the constant and severe hunger, in people with Prader-Willi syndrome ages 4 and older. It was FDA-approved on March 26, 2025 and launched in the U.S. in the second quarter of 2025. Growth hormone therapy remains a separate treatment for short stature and poor muscle development in PWS.
▸How is Vykat XR taken?
Vykat XR is taken by mouth once a day, with or without food, and tablets must be swallowed whole, not split, crushed, or chewed. The dose is based on body weight and is raised step by step over about 6 weeks to a target dose, with a maximum of 525 mg a day. Blood sugar and HbA1c are checked before starting and during treatment.
▸What are the side effects of Vykat XR?
Common side effects of Vykat XR (in 10% or more of patients) include excess body hair growth, swelling from fluid retention, high blood sugar, and skin rash. High blood sugar can be severe and in some patients has progressed to diabetic ketoacidosis, and severe fluid overload including fluid in the lungs has been reported. Vykat XR is not recommended in patients with kidney or liver impairment, and it may harm an unborn baby.
▸What did the Vykat XR clinical trial show?
FDA approval of Vykat XR was based on a 16-week randomized withdrawal study (NCT03714373) in 77 people with PWS who had already taken the drug for an average of 3.3 years. Those switched to placebo had significantly worse hyperphagia than those who stayed on Vykat XR. The earlier 13-week DESTINY PWS study in 126 patients is the main source of the label's safety data.
Sources and references
Every factual claim on this page is drawn from the public sources listed below. Click any reference to open the original document.
- U.S. National Library of Medicine, DailyMed · 2025-03. VYKAT XR (diazoxide choline) extended-release tablets: prescribing information. https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0e745e85-9512-e360-e063-6394a90aebf1
- U.S. Food and Drug Administration. VYKAT XR, NDA 216665. https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=overview.process&ApplNo=216665
- Soleno Therapeutics investor relations · 2017-03. Capnia Completes Merger With Essentialis, Creating Rare Disease Therapeutics Company. https://investors.soleno.life/news-releases/news-release-details/capnia-completes-merger-essentialis-creating-rare-disease
- Neurocrine Biosciences via Nasdaq · 2026-05-18. Neurocrine Biosciences Completes Acquisition of Soleno Therapeutics. https://www.nasdaq.com/press-release/neurocrine-biosciences-completes-acquisition-soleno-therapeutics-2026-05-18