Exenatide (Byetta / Bydureon)_Dosage, benefits & legal status
Also known as Byetta, Bydureon, Bydureon BCise, Exenatide, exendin-4, AC2993
The first GLP-1 drug, found in lizard venom, now mostly retired.
Common vial size is what vendors typically sell, not a recommendation. Enter your own vial in the calculator.
What is Exenatide (Byetta / Bydureon)?
Plain language first. The technical label stays, but it never stands alone.Overview
This is where the whole Ozempic family started. It is still approved, but it has largely been left behind by newer drugs that work better and are taken less often.
Exenatide was the first GLP-1 drug ever approved. It is a copy of a substance found in the saliva of the Gila monster, a venomous lizard, which turned out to act on the same receptor as the human gut hormone GLP-1 while lasting much longer.
What it's used for
An older injection for type 2 diabetes, taken to lower blood sugar. It is rarely a first choice now.
How does Exenatide (Byetta / Bydureon) work?
What it does in the body, and where.Exenatide is a copy of a lizard-venom peptide that happens to fit the human GLP-1 receptor. It survives in the body far longer than the human hormone does.
- 01It came from Gila monster salivaResearchers noticed a substance in the venom acted like GLP-1 but lasted hours instead of minutes.
- 02It binds the GLP-1 receptorThe same target every drug in this family uses, including semaglutide.
- 03Insulin goes up only when blood sugar is highThe signal quietens when blood sugar falls, so low blood sugar is uncommon unless it is combined with other diabetes drugs.
- 04Why it lost groundIt shares only about half its sequence with human GLP-1, and some people develop antibodies that blunt the effect. Newer drugs are closer copies and work better.
Acts on one receptor.
What else is it used for?
Each use below carries its own evidence level. Approved means regulators have cleared it for that purpose. Investigational means it is in trials. Early research means it is being studied and is not established.
- Lowering blood sugar in type 2 diabetesFDA-approved
- Weight loss, where the effect is smaller than semaglutide or tirzepatideClinical use
The published record
Papers and trials about Exenatide (Byetta / Bydureon)
341 papers tagged human · 172 not reviews or lab · 64 clinical trial publications
378 registered trials · 37 with posted results
Furthest stage reached: Approved in the US
Counted from Europe PMC indexing, not read by a person; a human tag can land on reviews, commentary or lab papers; clinical trial publications is the narrower count. 500 papers and 100 trials indexed in detail.
At a glance
Four things to know about Exenatide (Byetta / Bydureon)
Evidence
FDA-approved
Category
Weight loss and metabolic
Common vial
2 mg
Half-life
About 2.4 hours for the twice-daily form
How much, and do you cycle it?
The range, and whether you take breaks.2 mg per week (the weekly form), weekly. Taken continuously, with no planned break FDA label
Blood sugar rises again when it stops. The label sets no end date.
About 2.4 hours for the twice-daily formFDA label
This is Byetta, the twice-daily product, and the label adds that exenatide is measurable for about 10 hours after a dose. The extended-release product, Bydureon BCise, is a depot formulation and behaves completely differently, so the two do not share a number.
Source: Byetta label section 12.3, DailyMed setid 53d03c03-ebf7-418d-88a8-533eabd2ee4f
You can compare this against the whole library to see where it sits.
How do I dose and price it?
Enter your vial and your dose. Pick a mix. We show the draw and the cost.The vial holds a fixed amount of drug. Adding more water does not make more drug, it just spreads it thinner, so you draw a bigger number on the syringe for the same dose.
Choose your mix
Measuring the water1 mL = one full 100-unit syringe.
How do you store it?
Before mixing, and after.Dry powder in the freezer or fridge. Once mixed, fridge, and use within about a month.
Unmixed lyophilized Exenatide (Byetta / Bydureon) keeps for a long time cold. Once you add water the clock starts: most reconstituted vials hold up for roughly 28 to 30 days at fridge temperature. Keep it out of light, and do not freeze it after mixing.
What are the side effects and cautions?
Known cautions and warnings for this compound.Two very different products share this name and only one is still sold. Byetta was the twice-daily version at 5 or 10 micrograms, and it was discontinued in 2025. Bydureon BCise is the weekly version at a fixed 2 mg, and that is what remains. A dose you read about in an older article is probably the twice-daily one, and the two are not interchangeable.
Solubility, computed: 28% charged residues, 38% hydrophobic. Water usually sufficient.
A first-pass rule from peptide manufacturers' guidance. It does not account for disulfide bridges, salt form or how the powder was dried, and it predicts what should be easy rather than what will happen in your vial.
Who should avoid it
- A personal or family history of medullary thyroid cancer, for the weekly form
- Multiple Endocrine Neoplasia syndrome type 2, an inherited hormone condition
- Severe kidney problems
- A history of pancreatitis
- Pregnancy, without talking to your doctor
Stop and get help
- Severe stomach pain that does not go away, which can signal pancreatitis
- A lump or swelling in the neck, trouble swallowing, or a hoarse voice
- Signs of an allergic reaction such as face or throat swelling, hives, or trouble breathing
- Much less urine than usual, which can signal kidney trouble
Common effects
- Nausea, which is common and often the reason people stop
- Vomiting or diarrhea
- Injection-site lumps with the weekly form
- Headache
- Modest weight loss, smaller than the newer drugs
Where this page says nothing is established, that means nobody has studied it, not that a compound is safe.
Is Exenatide (Byetta / Bydureon) approved?
And where the numbers on this page come from.Yes. Exenatide (Byetta / Bydureon) is FDA approved and available on prescription in the United States.
- Approval statusFDA-approved
- RouteUnder the skin (subcutaneous)
- Checked14 August 2026
- DoseFrom the drug label. The manufacturer tested this range and a regulator reviewed it.
- Vial sizeFrom what vendors typically list; not a recommendation.
- Sources
What has happened recently
Approved in 2005, the first drug of its kind. The twice-daily Byetta was discontinued in 2025 and the weekly Bydureon BCise is the version still on the market. Two related older GLP-1 drugs, Tanzeum and Lyxumia, have also been withdrawn in the US. Approved for type 2 diabetes only, never for weight loss.
You can compare this against the whole library, or read how to check a seller.
What else is like Exenatide (Byetta / Bydureon)?
Others in GLP-1 agonists, side by side.If you're weighing Exenatide (Byetta / Bydureon), it's worth reading GZC8072, KAI-4729, and Lixisenatide (Adlyxin) in the same class.
The first GLP-1 drug, found in lizard venom, now mostly retired.
- Dose
- 2 mg per week (the weekly form)
- How often
- Weekly
An experimental weekly GLP-1 pill from China, made from a modified GLP-1 peptide, with no human results yet.
- Dose
- No dose disclosed
- How often
- Weekly (intended)
An experimental weekly GLP-1/GIP/glucagon triple agonist, not to be confused with retatrutide.
- Dose
- 1 up to 12 mg per week (trial doses)
- How often
- Weekly
An approved GLP-1 that lost the race and left the US market.
- Dose
- Set by the label
- How often
- Once daily
Guides for this compound
- How to Reconstitute a Peptide
Mix peptide powder with bacteriostatic water, step by step.
- How to Read an Insulin Syringe
Read the units, convert to millilitres, and draw the exact dose.
- mcg vs mg: The Peptide Dosing Mistake to Avoid
Your vial says mg and your protocol says mcg. Here is the conversion and how to check it.
- Why Does My Peptide Injection Itch or Welt
Injection-site irritation, a histamine reaction, or a true allergy, and how to tell them apart.
- Semaglutide vs Tirzepatide vs Retatrutide
One receptor, two, or three. Mechanism, trial weight loss, side effects, and real cost.
Sources
- FDA, BYDUREON BCise (exenatide extended-release) prescribing information(2021)Fixed 2 mg once weekly for type 2 diabetes. Boxed warning for thyroid C-cell tumors.
Beyond these, 600 records are indexed. Browse the records