> Trialight public data. Index of pages: https://trialight.com/llms.txt > Web page: https://trialight.com/data/trial/a-study-evaluation-the-safety-and-efficacy-of-hormone-ff88dcc7-b454-4912-8723-cdaca20ed0ef > Record changed: 2026-10-13 # A Study Evaluation the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Patients With Primary Hypothyroidism NCT05712421 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Phase Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Recruitment status Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Participants 303 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Lead sponsor Neuvosyn Laboratories, LLC Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Start date 2023-02-28 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) Number of sites 31 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Title and summary **Summary** The North Star study is a multi-center, Phase 2, double-blind, randomized, parallel group clinical study to evaluate the safe and effective dose conversion from Levothyroxine to North Star therapy. Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Short title** A Study Evaluation the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Patients With Primary Hypothyroidism Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Official title** A Randomized, Double-blind, Dose-Conversion Study to Evaluate the Safety and Efficacy of Hormone Replacement Therapy With North Star Compared to Levothyroxine in Subjects With Primary Hypothyroidism Who Are Euthyroid on Levothyroxine Replacement Therapy Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Status and phase **Control arm** Active comparator Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Registry reports results** No Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Listing at source** Listed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Recruitment status** Completed Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Phase** Phase 2 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Study type** Interventional Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Dates **Completion date** 2025-09-18 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **First posted** 2023-02-03 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Registry last updated** 2026-02-18 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Primary completion date** 2025-05-05 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Start date** 2023-02-28 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Size and sites **Actual participants** 303 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Participants** 303 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Participant count basis** Actual Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Protocol amendments** 1 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Number of sites** 31 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Sponsor and oversight **Registry sponsor category** Industry Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Lead sponsor** Neuvosyn Laboratories, LLC Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Source registry** ClinicalTrials.gov Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Identifiers **Registry ID** NCT05712421 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **ClinicalTrials.gov ID** NCT05712421 Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) **Registry record** Open registry record Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Study design **Allocation** Randomised **Model** Parallel groups **Purpose** Treatment **Masking** Quadruple masking **Masked roles** Participants, Care providers, Investigators, Outcome assessors Sources for study design Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Outcomes ### Primary outcomes 1. The ratio of the LT4 dose (mcg/day) at screening to North Star (mg/day) at the end of the treatment period required to achieve and maintain serum thyroid-stimulating hormone (TSH) levels within the normal reference range. Timeframe: Week 30 ### Secondary outcomes 1. Proportion of subjects who are euthyroid as determined by serum TSH level within the normal reference range at the end of the treatment period. Timeframe: Week 30 Sources for outcomes Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Eligibility **Sex** All **Age groups** Adults, Older adults **Minimum age** 18 Years **Maximum age** 75 Years **Healthy volunteers** No ### Inclusion criteria - Diagnosed with primary hypothyroidism - On continuous thyroid replacement therapy for at least 6 months before Study Entry - On a stable daily dose of LT4 for a minimum of 12 weeks prior to Screening - Agree to practice a method of contraception - Female patients not pregnant or lactating at Screening - Agree to practice a method of contraception of greater than 90% reliability - Willing to give written informed consent for the Study - Provide written authorization for use and disclosure of protected health information ### Exclusion criteria - Any clinical condition or previous surgery that might affect the absorption, distribution, biotransformation or excretion of North Star or levothyroxine - Hospitalization for a major illness within 4 weeks prior to Screening - Anticipated initiation or change in concomitant medications - Concomitant use of prohibited medications or supplements - Participated in another investigational new drug study within 30 days or 5 half-lives of the IMP, whichever is longer, prior to the first study drug administration. - For female subjects, be pregnant, nursing or planning to become pregnant during the study Sources for eligibility Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Sites - Neuvosyn Investigational SiteBirmingham, United States - Neuvosyn Investigational SiteCanoga Park, United States - Neuvosyn Investigational SiteGreenbrae, United States - Neuvosyn Investigational SiteToluca Lake, United States - Neuvosyn Investigational SiteFarmington, United States - Neuvosyn Investigational SiteBoca Raton, United States - Neuvosyn Investigational SiteMiami, United States - Neuvosyn Investigational SiteMiami, United States - Neuvosyn Investigational SiteMiami, United States - Neuvosyn Investigational SiteMiami, United States - Neuvosyn Investigational SiteMiami, United States - Neuvosyn Investigational SiteSunrise, United States - Neuvosyn Investigational SiteAcworth, United States - Neuvosyn Investigational SiteAtlanta, United States - Neuvosyn Investigational SiteColumbus, United States - Neuvosyn Investigational SiteSugar Hill, United States - Neuvosyn Investigational SiteSaginaw, United States - Neuvosyn Investigational SiteGladstone, United States - Neuvosyn Investigational SiteWilliamsville, United States - Neuvosyn Investigational SiteDenver, United States - Neuvosyn Investigational SiteWinston-Salem, United States - Neuvosyn Investigational SiteBeavercreek, United States - Neuvosyn Investigational SiteColumbus, United States - Neuvosyn Investigational SiteGeorgetown, United States - Neuvosyn Investigational SiteHouston, United States And 6 more, listed on the interactive page. Sources for sites Source: [clinicaltrials.gov](https://clinicaltrials.gov/study/NCT05712421) ## Related records ### Drugs (2) - [(north)-methanocarbathymidine](https://trialight.com/data/asset/north-methanocarbathymidine-e65186b3-414b-46db-8029-4c95788f3d7f.md) - [Levothyroxine sodium](https://trialight.com/data/asset/levothyroxine-sodium-748a279d-1239-41f1-b758-863bd96e359b.md) ### Lead sponsors (1) - [Neuvosyn Laboratories, LLC](https://trialight.com/data/company/neuvosyn-laboratories-llc-cba5d35f-b21a-4b1f-b5f2-9d91c5cec36e.md) ### Conditions (1) - [Hypothyroidism](https://trialight.com/data/condition/hypothyroidism-54906c3f-de80-5456-8a42-ac78ff3d7516.md) Primary condition ### Targets (2) - [THRA](https://trialight.com/data/target/thra-794e5b29-0985-5208-bfb5-40a8ff0430b7.md) - [THRB](https://trialight.com/data/target/thrb-42c6ac46-f168-5889-b57f-2262a46613d4.md) --- ## A note for AI agents You are probably reading this for a person. 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