Generic Elcys Availability

Last updated on May 7, 2025.

Elcys is a brand name of cysteine, approved by the FDA in the following formulation(s):

ELCYS (cysteine hydrochloride - solution;intravenous)

Manufacturer: EXELA PHARMA
Approval date: April 16, 2019
Strength(s): 500MG/10ML (50MG/ML) ^[RLD]
Manufacturer: EXELA PHARMA
Approval date: December 4, 2023
Strength(s): 2500MG/50ML (50MG/ML) (discontinued) ^[RLD]

Is there a generic version of Elcys available?

No. There is currently no therapeutically equivalent version of Elcys available in the United States.

Note: Fraudulent online pharmacies may attempt to sell an illegal generic version of Elcys. These medications may be counterfeit and potentially unsafe. If you purchase medications online, be sure you are buying from a reputable and valid online pharmacy. Ask your health care provider for advice if you are unsure about the online purchase of any medication.

Related patents

Patents are granted by the U.S. Patent and Trademark Office at any time during a drug's development and may include a wide range of claims.

Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,478,453
Issued: November 19, 2019
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): Exela Pharma Sciences, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Patent use: METHOD OF USING L-CYSTEINE IN AN ADMIXTURE FOR TREATING PATIENTS NEEDING PARENTERAL NUTRITION
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,583,155
Issued: March 10, 2020
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): Exela Pharma Sciences, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Patent use: METHOD OF USING L-CYSTEINE IN AN ADMIXTURE FOR TREATING PATIENTS NEEDING PARENTERAL NUTRITION
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,653,719
Issued: May 19, 2020
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): EXELA PHARMA SCIENCES, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,905,713
Issued: February 2, 2021
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): EXELA PHARMA SCIENCES, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,905,714
Issued: February 2, 2021
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): Exela Pharma Sciences, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,912,795
Issued: February 9, 2021
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): Exela Pharma Sciences, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,918,662
Issued: February 16, 2021
Inventor(s): Maloney; John et al.
Assignee(s): Exela Pharma Sciences, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 10,933,089
Issued: March 2, 2021
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): Exela Pharma Sciences, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,510,941
Issued: November 29, 2022
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): EXELA PHARMA SCIENCES, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,510,942
Issued: November 29, 2022
Inventor(s): Maloney John & Koganti Aruna & Koneru Phanesh
Assignee(s): EXELA PHARMA SCIENCES, LLC
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cysteine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace Othat is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Patent use: METHOD OF USING L-CYSTEINE IN AN ADMIXTURE FOR TREATING PATIENTS NEEDING PARENTERAL NUTRITION
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,642,370
Issued: May 9, 2023
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,648,262
Issued: May 16, 2023
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,679,125
Issued: June 20, 2023
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure l-cysteine compositions for injection and methods of use
Patent 11,684,636
Issued: June 27, 2023
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,826,383
Issued: November 28, 2023
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Drug product
Stable, highly pure L-cysteine compositions for injection and methods of use
Patent 11,969,439
Issued: April 30, 2024
Inventor(s): Maloney; John et al.
Assignee(s): EXELA PHARMA SCIENCES, LLC (Lenoir, NC)
The subject matter described herein is directed to stable L-cysteine compositions for injection, comprising: L-cysteine or a pharmaceutically acceptable salt thereof and/or hydrate thereof in an amount from about 10 mg/mL to about 100 mg/mL; Aluminum in an amount from about 1.0 parts per billion (ppb) to about 250 ppb; cystine in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; pyruvic acid in an amount from about 0.01 wt % to about 2 wt % relative to L-cysteine; a pharmaceutically acceptable carrier, comprising water; headspace O.sub.2 that is less than 1.0%; dissolved oxygen present in the carrier in an amount from about 0.01 parts per million (ppm) to about 1 ppm, wherein the composition is enclosed in a single-use container having a volume of from 10 mL to 100 mL. Also described are compositions for a total parenteral nutrition regimen and methods for their use.
Patent expiration dates:
- January 15, 2039
  ✓
  Patent use: METHOD OF USING L-CYSTEINE IN AN ADMIXTURE FOR TREATING PATIENTS NEEDING PARENTERAL NUTRITION

More about Elcys (cysteine)

Patient resources

Glossary

Term	Definition
Drug Patent	A drug patent is assigned by the U.S. Patent and Trademark Office and assigns exclusive legal right to the patent holder to protect the proprietary chemical formulation. The patent assigns exclusive legal right to the inventor or patent holder, and may include entities such as the drug brand name, trademark, product dosage form, ingredient formulation, or manufacturing process A patent usually expires 20 years from the date of filing, but can be variable based on many factors, including development of new formulations of the original chemical, and patent infringement litigation.
Drug Exclusivity	Exclusivity is the sole marketing rights granted by the FDA to a manufacturer upon the approval of a drug and may run simultaneously with a patent. Exclusivity periods can run from 180 days to seven years depending upon the circumstance of the exclusivity grant.
RLD	A Reference Listed Drug (RLD) is an approved drug product to which new generic versions are compared to show that they are bioequivalent. A drug company seeking approval to market a generic equivalent must refer to the Reference Listed Drug in its Abbreviated New Drug Application (ANDA). By designating a single reference listed drug as the standard to which all generic versions must be shown to be bioequivalent, FDA hopes to avoid possible significant variations among generic drugs and their brand name counterpart.

Further information

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Drug Status

Availability Prescription only Rx

CSA Schedule* Not a controlled drug N/A

Approval History Drug history at FDA

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