Scientific deep-dive
GLP-1 Drugs in Cushing's Syndrome: Weight Down, Cortisol Unchanged
A multicenter retrospective study of 20 adults with Cushing's syndrome found weight down 10.3 kg and HbA1c down 0.5% over a median 13 months, with ACTH and cortisol levels stable throughout.
In Cushing’s syndrome the obesity and the diabetes are consequences of cortisol excess, which makes the obvious question a nervous one: does a drug that changes metabolism disturb the hormonal picture, or the monitoring that depends on it? A multicenter retrospective study of 20 adults with biochemically confirmed Cushing’s found weight down 10.3 kg and HbA1c down 0.5% over a median 13 months, with ACTH and cortisol levels unchanged.[1] Twenty people is a small sample, but before this, the paper notes, the question was unexplored.
What was measured
The study included twenty adults with biochemically confirmed Cushing’s syndrome and concurrent type 2 diabetes and/or obesity, treated for at least three months with a GLP‑1 receptor agonist (liraglutide, semaglutide, tirzepatide or dulaglutide). Anthropometric, hemodynamic, metabolic, hepatic and hormonal parameters were compared before and after therapy. Median follow-up was 13 months.[1]
| Measure | Change | P |
|---|---|---|
| Body weight | −10.3 ± 8.8 kg | < 0.001 |
| BMI | −4.2 ± 2.8 kg/m² | < 0.001 |
| Fasting glucose | −12.1 ± 35.3 mg/dL | 0.015 |
| HbA1c | −0.5 ± 0.9% | 0.011 |
| ALT | −3.9 ± 21.4 U/L | 0.005 |
| GGT | −25.9 ± 57.3 U/L | 0.012 |
| Blood pressure, lipids | no significant change | — |
| ACTH and cortisol | remained stable | — |
Mild gastrointestinal side effects were reported in 26.3% of patients, and the drugs were described as generally well tolerated.[1]
What twenty retrospective patients cannot tell you
- There is no control group. Some of the weight and glucose change may reflect other treatment of the underlying Cushing's, which is what people with this condition are receiving.
- It is retrospective, so it reports what happened to be recorded rather than what was planned to be measured.
- Four different drugs are pooled into one group of twenty. Nothing here separates them.
- The blood pressure and lipid results showed no significant change, which matters in a condition where both are commonly deranged.
- Cushing's syndrome is managed by endocrinologists for good reason. This is information to bring to that conversation, not to act on alone. Which signs separate Cushing’s from ordinary weight gain is covered in buffalo hump and weight loss.
And acromegaly, where there is nothing
Acromegaly is routinely bracketed with Cushing’s when this question comes up, both being pituitary-driven disorders with metabolic consequences. We looked and could not find a cohort or case series reporting GLP‑1 outcomes in acromegaly. Rather than let the Cushing’s result stand in for both, we say plainly that this register has nothing to report on acromegaly.
Frequently Asked Questions
References
- 1.Iglesias P, Nobre EL, Hanzu F, et al. Efficacy and safety of GLP-1 receptor agonists in the treatment of type 2 diabetes and/or obesity in patients with Cushing's syndrome: a multicenter retrospective study Endocrine. 2026. PMID: 41803337.
Compare the sellers
Related research
AOD-9604: What the Evidence Shows
AOD-9604, a growth hormone fragment, failed its obesity trials: in 536 adults, weight loss beyond placebo was under 1 kg and the developer ended the program in 2007. FDA advisers voted 12 to 0 against compounding it.
9 min read
Best Injection for Weight Loss? Every Approved Shot, Ranked on Trial Data
Zepbound took off the most weight of any injection FDA has approved for weight, and beat semaglutide head to head. Wegovy has the proven cardiovascular benefit. Label and trial data on weight, side effects and dropouts, plus what is not approved yet.
8 min read
Eating Too Little on a GLP-1: What the Deficiency Data Show
Across 480,825 adults, more than 60% took in less calcium and iron than their estimated requirements, vitamin D deficiency reached 13.6% at a year, and ferritin ran 26–30% below an active comparator.
7 min read
The Cochrane Verdict, and Who Funded the Evidence
Two WHO-funded Cochrane reviews find weight loss likely to be sustained; the semaglutide review calls it clinically relevant. Both also note the trials were paid for by the manufacturers: all of them, in tirzepatide's case.
6 min read
GLP-1 Drugs and Type 1 Diabetes: The Label Says Unevaluated. Three Trials Disagree.
36% of people with type 1 diabetes and obesity hit a composite of time-in-range, low-glucose safety and 5% weight loss, against 0% on placebo. Total daily insulin fell about a third in a second trial.
7 min read
GLP-1 Drugs After 65: Strength, Not Just Weight
Grip strength held up in general adult trials even as lean mass fell. In older adults with type 2 diabetes, prolonged use has been linked to the opposite, and a 2024 review found no concise guidelines for this age group.
7 min read
Where to get tirzepatide online, safely: sellers our editors have checked
These are telehealth sellers our editors have checked. For each one we hold a price, the form the drug comes in, and the states it reaches.
No insurance needed · vetted by our editors
Some of the links on this page earn us money. If you sign up with a provider after following one, that provider may pay GLP Watchdog a commission. Learn more
Luvo Health
Moving between compounded and brand without changing seller
From $179/mo
Get started →Bodybuilding Health+
Seeing what it charges before you answer any medical questions
From $209/mo
Get started →HealthRX
From $214/mo
Get started →