How people get it: By prescription, usually as a weekly injection. Some come as pills.
The basics
What it is
GLP-1 agonists are man-made hormones that cause many of the same actions as the natural hormone. They were first developed to help people with type 2 diabetes control their blood sugar.
Source: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗
How it's thought to work
- GLP-1 is a natural hormone released by the gut after a meal.
- The natural hormone tells the pancreas to release insulin, which helps regulate blood sugar.
- The drugs slow digestion, so you feel fuller for longer.
Source: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗
What people use it for
- Semaglutide injection is used to control blood sugar in certain people with type 2 diabetes.
- Semaglutide injection is used to lower the risk of heart attack, stroke, or death in adults with type 2 diabetes and heart and blood vessel disease.
- Semaglutide injection is used to assist with weight loss in certain people who are obese or overweight.
- Semaglutide injection is also used to treat a liver disease called MASH.
- Tirzepatide injection is used to treat obstructive sleep apnea in adults with obesity.
- GLP-1 drugs alone cannot treat diabetes or obesity and work best with lifestyle changes.
Sources: MedlinePlus (NIH): Semaglutide Injection: MedlinePlus Drug Information ↗ · MedlinePlus (NIH): Tirzepatide injection: MedlinePlus Drug Information ↗ · MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗
What the research has found so far
Some GLP-1 drugs have proven positive effects on sleep apnea and knee osteoarthritis. Many people using GLP-1 drugs will regain lost weight if they stop taking the medicine.
Source: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗
Approved for diabetes and weight. Large trials are now looking at heart, kidney and brain aging.
On GLP-1 drugs and aging, PubMed lists 30 trials in people, 61 studies that watched people over time, 140 animal and lab studies. See the counts and searches
Stage 4 because it is FDA-approved for chronic weight management (Wegovy and Zepbound labels). See the source ↗
A stage shows how far research has got, not whether it will work for you. How stages work
Side effects and risks
- Listed side effects of GLP-1 drugs include nausea, vomiting, diarrhea, belly pain, loss of appetite, constipation, and headache.
- Other listed side effects are low blood sugar, reduced muscle mass, and injection site reactions such as rash or itching.
- Pancreatitis and gallbladder disease are listed as rare.
- Most side effects occur with a higher dose and get better with time as the body adjusts.
- Semaglutide injection may also cause heartburn, burping, a runny nose or sore throat.
- Mayo Clinic lists hair loss as a less common semaglutide effect.
- Tirzepatide may cause nausea, vomiting, diarrhea, decreased appetite, constipation, and upset stomach.
- Serious tirzepatide side effects include stomach pain that will not go away, which may spread to the back.
Sources: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗ · MedlinePlus (NIH): Semaglutide Injection: MedlinePlus Drug Information ↗ · Mayo Clinic: Semaglutide (subcutaneous route) - Side effects & dosage - Mayo Clinic ↗ · MedlinePlus (NIH): Tirzepatide injection: MedlinePlus Drug Information ↗
Who should be careful, and drug interactions
- GLP-1 drugs are not recommended for pregnant women, people with a history of medullary thyroid cancer, or people with a family history of MEN II.
- Low blood sugar has a higher risk if the drugs are taken with insulin or sulfonylureas.
- The semaglutide page says doctors will probably tell people with a history of thyroid tumors or MEN 2 not to use it.
- Semaglutide users are told to stop it 2 months before a planned pregnancy.
- Tirzepatide may decrease the effectiveness of hormonal birth control.
- People having surgery, including dental surgery, are told to tell their doctor or dentist about semaglutide use.
- Semaglutide should not be used in people with type 1 diabetes or diabetic ketoacidosis.
- Semaglutide use is not recommended in severe gastroparesis, where the stomach does not empty normally.
- Mayo Clinic says semaglutide should be used with caution in people with pancreatitis history, kidney disease, dehydration, digestion problems, or diabetic retinopathy.
- Mayo Clinic notes that elderly patients are more sensitive to the effects of semaglutide than younger adults.
- Mayo Clinic says drinking alcohol may cause severe low blood sugar.
Sources: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗ · MedlinePlus (NIH): Semaglutide Injection: MedlinePlus Drug Information ↗ · MedlinePlus (NIH): Tirzepatide injection: MedlinePlus Drug Information ↗ · Mayo Clinic: Semaglutide (subcutaneous route) - Side effects & dosage - Mayo Clinic ↗
Approval and legal status
Amounts used in studies
What studies or labels describe, not a recommendation.
- The page says that the higher the dose, the more the effect.
- GLP-1 drugs are most often given as an injection, either daily or weekly, and one type is a pill.
- Semaglutide injection (Ozempic) is given once a week.
- The semaglutide injection page says doctors will probably start with a low dose and increase it after 4 weeks.
- Mayo Clinic lists a starting adult semaglutide dose of 0.25 mg once a week for 4 weeks.
- The tirzepatide page says the dose is gradually increased, not more than once every 4 weeks.
Sources: MedlinePlus (NIH): GLP-1 agonists: MedlinePlus Medical Encyclopedia ↗ · MedlinePlus (NIH): Semaglutide Injection: MedlinePlus Drug Information ↗ · Mayo Clinic: Semaglutide (subcutaneous route) - Side effects & dosage - Mayo Clinic ↗ · MedlinePlus (NIH): Tirzepatide injection: MedlinePlus Drug Information ↗
Roughly what it costs
We don't have prices for this yet.
Questions to ask your doctor
- Is GLP-1 drugs a sensible option for me, given my health and the medicines I take?
- Could GLP-1 drugs interact with any medicine or supplement I already take?
- What side effects should I watch for, and when should I stop or call you?
- Would GLP-1 drugs be used for its approved purpose, or off-label for aging?
- How would we tell whether it is helping, and when should we review it?
This is general information gathered from the sources listed, not medical advice. Talk to your doctor before starting anything new.
What experts say
No expert views collected yet. Each one we add names the person and links to where they said it.
Recent research
New studies that mention GLP-1 drugs appear here after the morning update.
Trials
ClinicalTrials.gov lists 132 registered trials that mention GLP-1 drugs, for any condition (the count in The science below). Here we show the ones about aging. See them all ↗
The science
Counted from PubMed and ClinicalTrials.gov on Oct 17, 2026, using one search for GLP-1 drugs in relation to aging. Each link opens the exact search.
- Randomized trials in people
- 27 search ↗
- Large trials (multicenter or phase 3)
- 7 search ↗
- Phase 3 trials
- 4 search ↗
- Trials in people
- 30 search ↗
- Studies that watched people over time
- 61 search ↗
- Animal and lab studies
- 140 search ↗
- Registered trials
- 132 search ↗
PubMed search used
("GLP-1 receptor agonist*"[tiab] OR "glucagon-like peptide-1"[tiab] OR semaglutide[tiab] OR tirzepatide[tiab] OR liraglutide[tiab]) AND (aging[tiab] OR ageing[tiab] OR longevity[tiab] OR lifespan[tiab] OR "life span"[tiab] OR healthspan[tiab] OR "Aging"[mh] OR "Longevity"[mh] OR dementia[tiab] OR "cognitive decline"[tiab])
Counts are search results, so they include some records that only mention GLP-1 drugs. How we count