Last updated: May 27, 2026
Unithroid Suppliers (Manufacturers, API Sources, and Contract Fill-Finish) for Levothyroxine Sodium Tablets
Unithroid is a brand of levothyroxine sodium tablets (US: NDA 50747) marketed by Ascent Pharmaceuticals, Inc. and manufactured by Dr. Reddy’s Laboratories, Ltd. (tablet manufacturing) with ongoing sourcing of levothyroxine sodium API from pharmaceutical-grade supply chains used across levothyroxine generics. The supplier map for Unithroid is therefore best treated as a finished-dose manufacturing plus API procurement structure rather than a single “one-source” vendor model.
Who manufactures Unithroid tablets and what company is the NDA holder?
NDA holder (marketing): Ascent Pharmaceuticals, Inc.
Drug product manufacturer (tablets): Dr. Reddy’s Laboratories, Ltd.
What that means operationally: Finished-dose responsibility for Unithroid tablets sits with the manufacturer of record for the tablet dosage form, while Ascent controls commercial ownership and regulatory filings tied to NDA 50747.
Unithroid product scope relevant to supplier mapping
- Dosage form: tablets
- Active ingredient: levothyroxine sodium (thyroid hormone replacement)
- Therapeutic category: thyroid hormone (levothyroxine)
- Key practical implication: supplier discussions for Unithroid typically refer to (1) tablet manufacturing and (2) upstream API sourcing and control strategy for levothyroxine.
What are the upstream API suppliers for levothyroxine sodium used in Unithroid?
Levothyroxine sodium API sourcing is typically multi-sourced in the US market. For Unithroid specifically, public-facing label/registry details usually identify the drug product manufacturer more reliably than the API supplier name.
What can be asserted from public regulatory-style supply chain patterns:
- Levothyroxine sodium is a widely produced small-molecule API with multiple certified producers across regions.
- Finished-dose manufacturers (such as Dr. Reddy’s) generally purchase API through controlled supplier programs and manage incoming specification compliance, route consistency, and stability requirements for tablet manufacture.
- API supplier identities for a branded product may be disclosed through limited submissions, but are often not listed on consumer-facing packaging.
Supplier takeaway for procurement and due diligence: the supplier picture you can validate quickly for Unithroid is the finished-dose manufacturing and the controlled chain-of-custody for API, with API vendor names requiring verification through FDA manufacturing site data, DMFs, or audited supplier documentation.
Which contract manufacturing and fill-finish sites support Unithroid?
Unithroid is a tablet product. For contract manufacturing and supply chain mapping, the most actionable data point is the drug product manufacturer of record, which for Unithroid tablets is Dr. Reddy’s Laboratories, Ltd.
What “supplier” means for tablets like Unithroid
For tablets, “fill-finish” is not typically the primary contract step like it is for injectables or inhalations. Supplier responsibility typically includes:
- tablet compression and coating (if applicable)
- blend formulation and strength-specific manufacturing runs
- packaging line operations (bottles/blisters) under labeled packaging controls
- stability and release testing coordination under cGMP
What does the label and regulatory listing show about Unithroid suppliers?
For Unithroid, the label and listings consistently distinguish:
- NDA holder (commercial owner)
- drug product manufacturer (manufacturing site responsible for drug product)
- imprint/strength attributes across strengths (manufacturing batch records tied to strengths)
Actionable identifier: the drug product manufacturing site tied to NDA 50747.
Are there multiple manufacturers for Unithroid tablets?
For many legacy endocrine replacements, the branded product may show manufacturing transfers or supplemental manufacturing arrangements over time. For Unithroid, the most supportable public statement is:
- Dr. Reddy’s Laboratories, Ltd. is the identified tablet manufacturer associated with the Unithroid product.
Whether there are additional tablet manufacturing sites for specific lots or strength ranges requires lot-level sourcing analysis and regulatory site mapping, which is not deterministically public in a single consolidated list.
Unithroid vs generic levothyroxine: how do suppliers differ?
Supplier model comparison
Unithroid (brand):
- NDA holder with defined manufacturing responsibilities per labeled manufacturing site(s)
- commercial continuity tied to a specific drug product manufacturer relationship
Generic levothyroxine tablets:
- many companies sell levothyroxine and use different tablet manufacturers and API procurement networks
- high frequency of site changes across manufacturers because product lifecycle management is decentralized
Practical supplier risk for procurement
If you are evaluating Unithroid as a supply source against generics:
- brand supply risk is often less about “API availability” and more about tablet manufacturing capacity, packaging capacity, and release testing throughput.
- generic supply risk varies across vendors because API and tablet manufacturing are more fragmented.
What patent or exclusivity constraints affect supplier switching for Unithroid?
This question typically controls whether manufacturers can switch quickly to alternative suppliers, but API and drug product supply is governed by manufacturing capability and regulatory control rather than patents on levothyroxine itself.
For levothyroxine sodium, the market is mature and competitive. Supplier switching usually hinges on:
- cGMP qualification of alternate API sources
- comparability studies if the change requires bridging or reporting
- packaging and labeling controls tied to NDA or CBE pathways
Supplier implication: patent exclusivity generally does not prevent API procurement substitution for a small-molecule platform when regulatory change requirements are met. The actual constraints are regulatory reporting and manufacturing qualification.
How do FDA listings identify Unithroid manufacturing and supply chain details?
For US market supply chain mapping, FDA-oriented sources most often used include:
- drug product listings associated with the NDA
- label statements identifying manufacturing responsibility
- manufacturing site information that can be cross-referenced with cGMP inspection programs
The key operational point for Unithroid is that the drug product manufacturer of record is the most reliable “supplier” identification in publicly indexed sources.
Which companies are competing for Unithroid-type levothyroxine tablet supply?
In the levothyroxine space, competition is broad. The relevant competitive set includes:
- branded levothyroxine products (other than Unithroid)
- multi-brand generic manufacturers
- API producers and large contract manufacturers producing levothyroxine tablets for multiple labelers
Procurement lens: Unithroid competes on reliability of labeled manufacturing and distribution continuity more than on uniqueness of API chemistry.
Key Takeaways
- Unithroid supplier identification that is consistently actionable: Dr. Reddy’s Laboratories, Ltd. is the identified manufacturer for Unithroid tablets, with Ascent Pharmaceuticals, Inc. as the NDA holder/marketer.
- API suppliers for levothyroxine sodium are generally multi-source in US practice; for Unithroid, upstream API vendor identities are often not listed publicly in a single authoritative “supplier roster.”
- For supply assurance planning, the most defensible due diligence path is to validate the tablet manufacturing site relationship tied to NDA 50747, then confirm API control strategy through documentation and quality agreements rather than expecting a public API name.
FAQs
1) Who is the NDA holder for Unithroid?
Ascent Pharmaceuticals, Inc.
2) Which company manufactures Unithroid tablets?
Dr. Reddy’s Laboratories, Ltd.
3) Is Unithroid made by the same company that sells it?
No. The NDA holder/marketer is Ascent Pharmaceuticals, while tablet manufacturing is associated with Dr. Reddy’s Laboratories.
4) Are there multiple Unithroid manufacturers or only one manufacturing site?
Publicly, Dr. Reddy’s Laboratories, Ltd. is the key identified manufacturer for the tablets, but lot-level site multiplicity can occur over time and is best validated through regulatory and distribution records.
5) Who supplies the levothyroxine API for Unithroid?
Unithroid uses levothyroxine sodium API procured within the manufacturer’s qualified supply chain. The API supplier name is not reliably presented in a single public listing tied to Unithroid in the way the drug product manufacturer is.
References
- FDA. Drug Approval Reports and labeling resources for NDA 50747 (Unithroid). U.S. Food and Drug Administration.
- FDA. Orange Book and related NDA product listings for Unithroid (levothyroxine sodium tablets). U.S. Food and Drug Administration.
- FDA. Drugs@FDA entry for Unithroid (levothyroxine sodium). U.S. Food and Drug Administration.
