Semaglutide Explained: The What, How, Who, When, Where, and Why

Semaglutide is one of the most talked-about prescription medications of recent years, and much of what is written about it is either promotional or highly technical. This guide answers six basic questions in plain language: what it is, how it works, who it is and is not for, when it is taken, where it comes from, and why follow-up matters. It is educational and does not replace medical advice.

What is it?

• Semaglutide is a prescription medication in a class called GLP-1 receptor agonists
• It is a manufactured version of GLP-1, a hormone the gut releases after eating
• It was first approved for adults with type 2 diabetes, and later for chronic weight management
• It is available only with a prescription

How does it work?

• It activates the same receptors as the natural GLP-1 hormone, and lasts much longer in the body
• It signals fullness to the brain
• It slows the rate at which the stomach empties
• It takes part in blood sugar regulation by acting on the pancreas

It is not a stimulant, and it does not burn fat directly. How it works does not predict how any one person will respond.

Who is it for, and who is it not for?

It may be considered for

• Adults who meet weight criteria set out in FDA-approved labeling, as assessed by a licensed provider
• People whose health history shows no condition that rules it out

It is not used in

• People with a personal or family history of medullary thyroid carcinoma
• People with Multiple Endocrine Neoplasia syndrome type 2
• Pregnancy

Extra caution is needed with

• A history of pancreatitis or gallbladder disease
• Kidney problems
• Diabetic eye disease
• Use of insulin or a sulfonylurea
• A history of an eating disorder

When and how is it taken?

• Weekly injection. A small injection under the skin on the same day each week
• Daily tablet. Some services, including Nu Image, also prescribe a daily rapid-dissolve tablet
• Treatment starts at a low dose
• The dose is increased gradually, as directed by the provider
• It is used alongside nutrition, physical activity, and follow-up

Where does it come from?

This is the question people most often overlook.

• FDA-approved products. Brand-name semaglutide products have been reviewed by the FDA for specific uses.
• Compounded semaglutide. Prepared by state-licensed pharmacies for individual prescriptions. It is not FDA-approved, it is not a generic, and it has not been reviewed by the FDA for safety, effectiveness, or quality.
• Unapproved products sold online. Vials sold without a prescription or labeled "for research use" should not be used.

The semaglutide prescribed through Nu Image is compounded. Published research on semaglutide was carried out with FDA-approved products, mainly as injections.

Why does follow-up matter?

• Side effects are most likely when a dose is started or raised
• A dose that is too high for you can be lowered
• With compounded vials, measuring errors are a known risk, so each dose should be confirmed in both milligrams and syringe units
• Other medications and planned procedures need to be taken into account
• Decisions about continuing or stopping should be made with a provider

Common side effects

• Nausea
• Constipation or diarrhea
• Feeling full quickly
• Occasional vomiting
• Heartburn or stomach discomfort

When to seek urgent care

• Severe abdominal pain that does not go away
• Repeated vomiting or inability to keep fluids down
• Sudden changes in vision
• Swelling of the face or throat, or trouble breathing
• A lump or swelling in the neck, hoarseness, or trouble swallowing

What stays your part

• Eating smaller portions and enough protein
• Drinking fluids steadily
• Strength training twice a week
• Reporting side effects early
• Telling every clinician and any surgical team that you take it

Questions to ask a provider

• Is semaglutide appropriate with my health history?
• Is the product FDA-approved or compounded?
• Which format do you recommend for me?
• How will my dose increase?
• Which symptoms mean I should call?

Evaluation through Nu Image

Nu Image offers online evaluations with licensed providers, who review your health history and decide whether a prescription is appropriate. Compounded semaglutide is available through Nu Image as a weekly injection or a daily rapid-dissolve tablet. It is not FDA-approved.

This content is for educational purposes only and is not medical advice, diagnosis, or treatment. It does not list every side effect or precaution. Compounded medications are prepared by state-licensed compounding pharmacies and are not reviewed or approved by the FDA for safety, efficacy, or quality. Prescription products require an online consultation with a licensed healthcare provider, who will determine whether a prescription is appropriate.