An observational study in Cortisol and Cortisol Binding Globulin, sponsored by Norfolk and Norwich University Hospitals NHS Foundation Trust. Completed at 1 site in United Kingdom. Open to female participants aged 18 Years to 90 Years. Per ClinicalTrials.gov, last updated 2026-11-10.
Sponsored by Norfolk and Norwich University Hospitals NHS Foundation Trust · Observational
Cortisol is a hormone that helps the body handle stress and maintain blood pressure. Doctors check if the adrenal glands (which make cortisol) are working correctly using a Synacthen test (SST). This test involves giving a drug that stimulates cortisol production and measuring how much is released.
For women taking oestrogen pills (found in birth control and hormone replacement therapy), the test results can be misleading. Oestrogen increases a substance in the blood called cortisol-binding globulin (CBG), which attaches to cortisol and makes some of it inactive. When doctors measure cortisol, they check both active and inactive forms. If CBG is high, the test can falsely suggest cortisol levels are normal, making it harder to tell if the adrenal glands are working correctly.
To avoid this problem, women taking oestrogen pills and gels/patches (transdermal) are asked to stop for 6 weeks before the test so that CBG/cortisol levels return to normal. However, this can cause uncomfortable symptoms like hot flushes, mood swings, and headaches.
Some women use transdermal oestrogen, which is absorbed through the skin instead. Unlike pills, there is some evidence that transdermal oestrogen doesn't affect CBG levels meaning women using them may not need to stop before an SST. This study will provide more evidence confirming that transdermal oestrogen is safe to continue before testing.
We will study three groups: women taking oestrogen pills, women using gel/patches, and women not taking oestrogen. By measuring CBG and cortisol every week, we aim to find out exactly when CBG returns to normal after stopping oestrogen pills. If it happens before 6 weeks, doctors may be able to shorten the break, making testing more manageable and more comfortable.
This research could improve testing for women taking oestrogen, potentially allowing those on gel/patches to continue treatment and those on pills to pause for a shorter time before testing.
Norfolk and Norwich University Hospitals NHS Foundation Trust is the lead sponsor of 30 studies on the registry; 9 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Norfolk and Norwich University Hospitals NHS Foundation Trust
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ALT and AST (liver enzymes)
Two enzymes measured in a routine blood test of the liver. Higher levels can mean the liver is under strain or damaged. SGPT and SGOT are older names for ALT and AST.
Criteria usually give a limit as a multiple of the upper limit of normal (ULN), often higher when cancer has spread to the liver.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
ULN (upper limit of normal)
The top of the normal range for a blood test, as set by the laboratory that runs it. Each lab prints its own range next to your result.
“≤ 2.5 × ULN” means the result can be up to two and a half times that top value.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Women taking oestrogen pills - They will stop taking them for up to six weeks, as required for standard care.
Women using oestrogen gel or patches - They will stop taking them for up to six weeks, as required for standard care.
Women not taking any oestrogen - This control group will help compare results.
Changes in cortisol binding globulin (CBG) concentration and serum cortisol levels
The primary outcome measures are the changes in cortisol binding globulin (CBG) concentration and serum cortisol levels over a six-week period following the discontinuation of oral or transdermal oestrogen therapy. These will be assessed through weekly blood samples, with additional comparison to salivary cortisol levels. The aim is to evaluate the impact of oestrogen route on CBG and cortisol levels, and to determine whether the current 6-week cessation period for oral oestrogen prior to the Short Synacthen Test (SST) can be safely shortened. This could improve test accuracy, patient experience, and potentially support the continued use of transdermal oestrogen without interruption.
Time frame: 6 weeks
Salivary cortisol and cortisone levels
Salivary cortisol and cortisone levels measured weekly over the 6-week period, to evaluate their potential as non-invasive alternatives to serum cortisol for assessing adrenal function.
Time frame: 6 weeks
PDFs hosted by the registry, ClinicalTrials.gov.
Plan to share: No
Ran from Feb 2026 to primary completion in Aug 2026, 5 months.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Norfolk and Norwich University Hospitals NHS Foundation Trust