Prescription medicine
Tasimelteon Brand names: Hetlioz
Tasimelteon (Hetlioz) is a prescription medicine with an FDA approval on record since 2014. FDA's NDC Directory lists it from 3 generic labelers, and pharmacies paid $228.25 per tasimelteon 20 mg capsule in the October 7, 2026 NADAC survey.
- Generic listed
Check it at the source: the tasimelteon FDA label on DailyMed (effective August 4, 2026, Vanda Pharmaceuticals Inc.); the NDA 205677 record on Drugs@FDA; every tasimelteon label on DailyMed.
Highlights of the record
FDA label of August 4, 2026; NDC Directory, Drugs@FDA and Orange Book, October 8, 2026; NADAC October 7, 2026
Used for
From the label: indications and usageHETLIOZ is a melatonin receptor agonist.
Forms and strengths
- 20 mg
- 4 mg/ml
Capsule; suspension; gelatin-coated capsule.
On the market
- Earliest approval on file
- January 31, 2014 Hetlioz, Vanda Pharms Inc; Drugs@FDA’s file, where older or withdrawn approvals can be missing
- Generic approvals
- 3 first December 12, 2022; 3 with a marketed status in Drugs@FDA
- Labelers listed (NDC)
- 4 of which 3 under generic applications, 1 under brand applications, repackagers included
- Last listed patent
- February 21, 2041 Hetlioz capsules; not a generic launch date
Supply and safety
- Pharmacy cost (NADAC)
- $228.25 per capsule Tasimelteon 20 mg capsule
- Shortage (FDA)
- No current entry
- Recalls by its makers (FDA)
- No recall recorded
- FAERS reports
- 5,770 through July 30, 2026
What is tasimelteon used for?
From the label: indications and usageHETLIOZ is a melatonin receptor agonist. […]
FDA pharmacologic class: Melatonin Receptor Agonist.
Source: FDA drug label (Hetlioz), Vanda Pharmaceuticals Inc., effective August 4, 2026 (SPL set ca4a9b63-708e-49e9-8f9b-010625443b90), via openFDA; the full label on DailyMed
Is there a generic for tasimelteon (Hetlioz)?
The FDA approved the first generic tasimelteon on December 12, 2022. 3 generic applications are approved; 3 of them carry a current (not discontinued) marketing status in Drugs@FDA; that status is not evidence that the generic is on sale.
FDA's NDC Directory lists tasimelteon from 3 labelers under a generic (ANDA) application and from 1 brand labeler. A listing means the company has registered the product for sale; it does not show that every pharmacy stocks it.
The Orange Book lists 31 patents for Hetlioz capsules: the compound patent runs to February 12, 2035, and the last listed entry to February 21, 2041. A patent or exclusivity date is not the date a generic goes on sale: court cases and settlements move it either way.
- 2014 earliest approval on file
- 2022 first generic approved
- 2041 last listed patent
Source: Drugs@FDA, FDA NDC Directory and the Orange Book (openFDA bulk files, October 8, 2026)
What do pharmacies pay for tasimelteon (Hetlioz)?
In CMS's NADAC survey of October 7, 2026, pharmacies paid $228.25 per Tasimelteon 20 mg capsule, down 46% from $419.01 on October 8, 2025. The survey records the price, not the reason for a change; large moves often follow a new generic or a list-price change. The chart's scale runs from the lowest to the highest price shown, not from zero. NADAC is what retail pharmacies paid their wholesalers, per unit, in CMS's monthly survey; what a patient pays depends on insurance and the pharmacy.
- Tasimelteon 20 mg capsule (generic)
| Strength and form | Brand or generic | Pharmacy cost | 30 tablets, or one pen or vial | 12-month change |
|---|---|---|---|---|
| Tasimelteon 20 mg capsule | Generic | $228.25 per capsule | $6,847.44 | -46% |
Source: CMS National Average Drug Acquisition Cost (NADAC) survey, October 7, 2026: what retail pharmacies paid per unit; not a counter price
What does the tasimelteon label say about other medicines?
The tasimelteon label names 4 other medicines in its interaction, contraindication or warning sections. The sentences are the labels' own; a label lists what its studies and reports found, not every interaction.
| Medicine named | Section | What the label says |
|---|---|---|
| Acebutolol | drug interactions | Antagonists (e.g., acebutolol, metoprolol) Beta-adrenergic receptor antagonists have been shown to reduce the production of melatonin via specific inhibition of beta-1 adrenergic receptors. |
| Fluvoxamine | drug interactions | DRUG INTERACTIONS Strong CYP1A2 inhibitors (e.g., fluvoxamine): Avoid use of HETLIOZ in combination with strong CYP1A2 inhibitors because of increased exposure ( 7.1 , 12.3 ) Strong CYP3A4 inducers (e.g., rifampin): |
| Metoprolol | drug interactions | Antagonists (e.g., acebutolol, metoprolol) Beta-adrenergic receptor antagonists have been shown to reduce the production of melatonin via specific inhibition of beta-1 adrenergic receptors. |
| Rifampin | drug interactions | DRUG INTERACTIONS Strong CYP1A2 inhibitors (e.g., fluvoxamine): Avoid use of HETLIOZ in combination with strong CYP1A2 inhibitors because of increased exposure ( 7.1 , 12.3 ) Strong CYP3A4 inducers (e.g., rifampin): |
Source: FDA drug label (Hetlioz), Vanda Pharmaceuticals Inc., effective August 4, 2026 (SPL set ca4a9b63-708e-49e9-8f9b-010625443b90), via openFDA; the full label on DailyMed
What do FAERS reports show for tasimelteon?
The FDA Adverse Event Reporting System holds 5,770 reports that list tasimelteon among the medicines taken, through July 30, 2026, each a report of something that happened, not proof the medicine caused it; 166 are coded as a death and 287 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is.
Reports received each year
The most reported reactions
Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026
What next?
- Other melatonin receptor agonists
- the pharmacologic class, with prices and generics
- Tasimelteon side effects
- the label's list beside FAERS reports
- Check an interaction
- what two or more labels say about each other