Condition category
Musculoskeletal Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims:
Approximately one in three adults suffer from night leg cramps (NLC) for which there are few safe and effective treatment options. Magnesium oxide supplementation has been explored and found ineffective; however, foam containing magnesium sulfate applied to the skin of the legs has not been examined. This study aims to investigate how well magnesium sulfate foam works in reducing NLC compared with foam containing no active ingredients (dummy foam) and whether it has an effect on quality of life. The goal is to find a treatment that will reduce night leg cramps and improve quality of life.

Who can participate?
Adults aged 18-75 years who are experiencing a minimum of 3 night leg cramps a week.

What does the study involve?
Participants who are experiencing at least 3 night leg cramps a week are asked to join the study. Participants will be randomly allocated either Foam A or Foam B to use daily for 14 days. Participants will write down how many nights they cramp and their daily symptoms (for example, pain level and severity of cramps) every day for 14 days. Participants will also fill out surveys on if they feel fatigued, their social function, sleep quality, and emotional well-being before they start using the foam and at the end of the 14 days.

What are the possible benefits and risks of participating?
There are no direct benefits for participating in the study, however there could be potential benefits for those that have success with the intervention treatment. The only risk will be for those participants that may have sensitive skin. In the event the participants have a reaction to the foam (for example, the skin gets irritated), the participant does not have to complete the study.

Where is the study run from?
Arnold School of Public Health Research Center, University of South Carolina (USA).

When is the study starting and how long is it expected to run for?
January 2017 to February 2018

Who is funding the study?
Avadim Health, Inc

Who is the main contact?
Toni M. Torres-McGehee

Trial website

Contact information



Primary contact

Prof Toni Torres-McGehee


Contact details

1300 Wheat Street
Blatt PE Center EXSC 212
United States of America



Additional contact

Dr Scott Strayer


Contact details

3209 Colonial Dr
United States of America

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effect of low pH magnesium sulfate foam on night leg cramps: A double-blind randomized trial


NLC Foam Study

Study hypothesis

We hypothesized that a topical foam with magnesium sulfate (Theraworx Relief®+Mg) would decrease night leg cramp (NLC) spasm frequency and severity and improve quality of life measures compared with a low pH topical foam (Theraworx Relief®-pH).

Ethics approval

University of South Carolina Institutional Review Board for Human Research, 1/9/2017. (Ame1_Pro00061216 by Expedited Review)

Study design

Randomized double-blind controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

Not available in web format, please use contact details to request a participant information sheet.


Night leg cramps


This was a home-based intervention within a Southeastern US urban community. Prior to enrolling participants in the study, all foam bottles were packaged by the manufacturer with the same label and shipping boxes were pre-labeled with A or B and shipped to the investigators. Advertisements were placed throughout primary care physician offices, pharmacies and the local university student health center in Columbia, SC, inviting individuals suffering from NLC to participate in the trial. Participants included were male and female adults who experienced a minimum of 3 night cramps per week. The participants were randomized to group A or B using the online randomization scheme sealed envelope™ ( As eligible participants enrolled in the study, they were assigned an ID number and corresponding group. Both investigators and participants were blind to the intervention treatments. The intervention group was given 5 bottles of low pH topical foam with magnesium sulfate (Theraworx Relief®+Mg) and followed a treatment plan for 14 consecutive days. The control group was given 5 bottles of the low pH topical foam (Theraworx Relief®-pH) and followed a treatment plan for 14 consecutive days. All pre- and post- data were collected within home and lab settings at the Arnold School of Public Health from May 2017 through February 2018. After all data was collected and analyzed, the manufacturer provided formulations of each foam to the investigators to determine group assignment.

Intervention type



Drug names

Primary outcome measure

Number of NLCs per week during the 14 consecutive days of the intervention

Secondary outcome measures

1. Social function assessed using the Restless Leg Syndrome Quality of Life Questionnaire at baseline and day 14
2. Daily function assessed using the Restless Leg Syndrome Quality of Life Questionnaire at baseline and day 14
3. Sleep quality assessed using the Restless Leg Syndrome Quality of Life Questionnaire at baseline and day 14
4. Emotional well-being were assessed by using the Restless Leg Syndrome Quality of Life Questionnaire at baseline and day 14
5. Daytime fatigue assessed using the Multi-Dimensional Fatigue Inventory at baseline and day 14

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Aged 18-75 years
2. Experiencing a minimum of 3 NLCs a week

Participant type


Age group




Target number of participants

50 was the target, however we were only able to recruit 36 to complete the entire study. We had a total of 57 inquiries, with 18 being excluded due to not meeting the criteria, and 7 did not return recruitment calls. We had 39 start the study, with 3 dropping out for non-compliance of the study or they didn't see immediate results.

Participant exclusion criteria

1. Patients nearing death
2. Taking medications causing NLCs
3. Adverse response to any topical foams
4. Allergy to magnesium or sulfur
5. Skin cuts
6. Active tissue or bone infections
7. Current foot or leg fractures

Recruitment start date


Recruitment end date



Countries of recruitment

United States of America

Trial participating centre

Public Health Research Center
921 Assembly Street
United States of America

Sponsor information


University of South Carolina - Institutional Review Board

Sponsor details

Blatt PE Center - Exercise Science
1300 Wheat St
United States of America

Sponsor type




Funder type


Funder name

Avadim Health Inc

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

We currently have already collected data and would like to register the trial and the submit for publication to JAMA Internal Medicine as soon as we get registered. Submission is pending registration of the trial.

IPD sharing statement:
The datasets generated during and/or analysed during the current study will be available upon request from Toni Torres-McGehee ( The study protocol, statistical analysis plan, and individual participant data that underlie the results reported in this article, after deidentification (text, figures, and tables) can be shared. Data will be available beginning 3 months and ending 5 years following article publication. Data will be available for researchers who provide a methodically sound proposal to achieve aims in the approved proposal. Proposals should be directed to To gain access, applicants will need to sign a data access agreement.

Intention to publish date


Participant level data

Available on request

Basic results (scientific)

Publication list

Publication citations

Additional files

Editorial Notes

19/12/2018: Internal review.