Zinc as an Adjunctive Therapy for Cervical Dystonia

May 12, 2026 updated by: University of Florida

Evaluation of Supplemental Zinc as an Adjunct to Prolong the Duration of Benefit After Botulinum Toxin Injections in Subjects With Cervical Dystonia

The goal of this clinical trial is to evaluate if supplemental zinc can prolong the duration of benefit of botulinum toxin injections in cervical dystonia patients receiving care at the University of Florida.

The main aims are:

  1. To evaluate the efficacy of zinc citrate supplementation in prolonging the duration of symptom relief provided by botulinum toxin type A (Botox) injections in cervical dystonia patients.
  2. To assess the safety and tolerability of zinc supplementation in this patient population.
  3. To analyze the potential influence of zinc supplementation on the quality of life and functional outcomes in cervical dystonia patients receiving Botox.

Researchers will compare zinc citrate to a placebo (a look-alike substance that contains no active drug) to see if zinc works to extend the effects of Botox.

Participants will:

Take zinc citrate or a placebo every day for 3 months, then cross over to the alternative treatment for another 3 months.

Visit the clinic every 3 months for Botox injections, check ups and surveys.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Study Design:

  • Randomized, single-blind, crossover placebo-controlled trial.
  • Participants: Approximately 20 patients diagnosed with cervical dystonia and currently receiving botulinum toxin (BoNT) type A (Botox) injections at the University of Florida (UF) Movement Disorders Clinic with good response to treatment as determined by treating neurologist will be enrolled into this study. The investigators plan to screen 25 patients to allow for screen failures and withdrawals.
  • Intervention: Participants will be randomized to receive either zinc citrate 30 mg supplementation or placebo starting immediately after their scheduled BoNT injection for 3 months. At a follow up BoNT injection, they will receive the alternative treatment for another 3 months. The total observation period is 6 months. Standard time between BoNT injections is 3 months.

The UF Movement Disorders Clinic follows approximately 1,500 cervical dystonia patients a year. The investigators do not anticipate any recruitment challenges.

Participants will be recruited during neurology clinic appointments and screening clinic appointments.

  • Patients will receive the same pattern of BoNT injections (muscle selection and dose) during the duration of the study.
  • Blood serum levels of zinc and vitamin B12 and complete blood counts (CBCs) will be measured at baseline and at the end of the study. Participants will be sent to UF Health Medical lab for blood draws and sample collection.
  • Written informed consent will be obtained from each participant before any study-specific procedures or assessments are performed.

Inclusion Criteria:

  • Adults aged 18-89 years.
  • Diagnosed with cervical dystonia.
  • Receiving regular BoNT type A (Botox) injections for at least six months.

Exclusion Criteria:

  • Known allergy or intolerance to zinc.
  • Significant comorbidities or concurrent medications that could interfere with study outcomes.
  • Pregnant or breastfeeding women.
  • Already taking a zinc supplement which would exceed tolerable upper intake level in adults (40 mg elemental zinc per day) with addition of zinc study supplement

Study Type

Interventional

Enrollment (Estimated)

25

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32608
        • Recruiting
        • Norman Fixel Institute for Neurological Diseases
        • Sub-Investigator:
          • Pooja Gupta, MD
        • Sub-Investigator:
          • Anastasia Barnes, MD
        • Principal Investigator:
          • Lauren Fanty, MD
        • Sub-Investigator:
          • Jerry Fenn, MD, PhD
        • Sub-Investigator:
          • Matthew Remz, MD
        • Sub-Investigator:
          • Jun Yu, MD
        • Sub-Investigator:
          • Irene Malaty, MD

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults aged 18-89 years.
  • Diagnosed with cervical dystonia.
  • Receiving regular BoNT type A (Botox) injections for at least six months.

Exclusion Criteria:

  • Known allergy or intolerance to zinc.
  • Significant comorbidities or concurrent medications that could interfere with study outcomes.
  • Pregnant or breastfeeding women.
  • Already taking a zinc supplement which would exceed tolerable upper intake level in adults (40 mg elemental zinc per day) with addition of zinc study supplement.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Zinc first
Encapsulated zinc citrate 30 mg orally daily for 3 months followed by placebo capsule matching zinc daily for 3 months
Drug: Placebo
Placebo
Drug: Zinc citrate
Oral zinc citrate 30 mg daily
Experimental: Placebo first
Placebo capsule matching zinc daily for 3 months, followed by encapsulated zinc citrate 30 mg orally daily for 3 months
Drug: Placebo
Placebo
Drug: Zinc citrate
Oral zinc citrate 30 mg daily

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Duration of Botox efficacy
Time Frame: 3 and 6 months post intervention
Time to return to baseline symptom severity using the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Severity Subscale. The TWSTRS Severity Subscale is scored from 0 to 35, with higher numbers indicating a more severe condition.
3 and 6 months post intervention

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Pain Severity
Time Frame: 3 and 6 months post intervention
Change in pain severity as measured by the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Pain Subscale. The TWSTRS Pain Subscale is scored from 0 to 20, with higher numbers indicating a more painful condition.
3 and 6 months post intervention
Change in Quality of Life
Time Frame: 3 and 6 months post intervention
Change in quality of life as measured by the Craniocervical dystonia questionnaire (CDQ-24). The CDQ-24 contains 24 items pertaining to quality of life in patients with cervical dystonia, scored from 0 ("never") to 4 ("very severely").
3 and 6 months post intervention
Change in Functional Disability
Time Frame: 3 and 6 months post intervention
Change in functional disability as measured by the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) Disability Subscale. The TWSTRS Disability Subscale is scored from 0 to 30 with higher numbers indicating a more disabling condition.
3 and 6 months post intervention
Patient Global Impression of Change
Time Frame: 3 and 6 months post intervention
Patient Global Impression of Change (PGIC) measures the patient's perception of the change in their condition after treatment, scored from 1 ("Very much improved") to 7 ("Very much worse").
3 and 6 months post intervention
Clinician Global Impression of Change
Time Frame: 3 and 6 months post intervention
The Clinician Global Impression of Change (CGIC) measures the researcher's perception of the change in the patient's condition after treatment, scored from 1 ("Very much improved") to 7 ("Very much worse").
3 and 6 months post intervention

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of Florida

Investigators

  • Principal Investigator: Lauren Fanty, MD, University of Florida

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 1, 2026

Primary Completion (Estimated)

May 31, 2027

Study Completion (Estimated)

May 31, 2027

Study Registration Dates

First Submitted

August 15, 2025

First Submitted That Met QC Criteria

August 22, 2025

First Posted (Actual)

August 26, 2025

Study Record Updates

Last Update Posted (Actual)

May 15, 2026

Last Update Submitted That Met QC Criteria

May 12, 2026

Last Verified

May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • IRB202500431

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Study researchers will be performing the analysis

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Cervical Dystonia

Clinical Trials on Placebo

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Thailand

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

3
Subscribe