Foundayo vs. Zepbound: pill vs. injection for weight loss

The Wegovy pill (semaglutide) unlocked a needle-free way to reap the weight loss rewards of a GLP-1. So when Eli Lilly, the maker of Zepbound (tirzepatide), announced a new oral GLP-1 for weight loss called Foundayo (orforglipron), you might have wondered: “Is this oral tirzepatide or Zepbound?” Not exactly.

Below, we unpack Foundayo vs. Zepbound, including differences in weight loss effectiveness, dosing, and cost.

At first glance, the biggest difference is that Foundayo is a daily oral tablet and Zepbound is a weekly subcutaneous (under-the-skin) injection.

Foundayo is an oral GLP-1 medication containingorforglipron. It’s made by Eli Lilly and was approved by the US Food and Drug Administration (FDA) for weight loss and management in adults with obesity or overweight and at least one weight-related condition. 

Zepbound is a weekly injection containing the GLP-1/GIP dual receptor agonist tirzepatide. It’s also made by Eli Lilly and is FDA-approved for two distinct uses:

• Weight loss in adults with obesity or overweight and a weight-related health condition

• Obstructive sleep apnea in adults with obesity

Here’s a snapshot of the key differences between Foundaya vs. Zepbound:

*To get the $299 price for the 14.5 mg and 17.2 mg doses of Foundayo, you must refill your prescription within 45 days of your previous fill. If you miss this window, the price of the specific doses increases to $349 per month. 

Fastest-working GLP-1 for faster weight loss

See if you qualify

Zepbound may be more effective for weight loss than Foundayo, according to clinical trial data. But individual weight loss journeys vary. Plus, there’s no head-to-head comparison study of these two weight loss drugs.

Here’s what we know about the effectiveness of Zepound vs. Foundayo:

• In a 72-week trial of Zepbound, participants lost about 15%–22% of their baseline body weight. Results were dose-dependent, meaning people on higher doses lost more weight.

• In a 72-week trial of Foundayo, participants lost 7.5%–11.2% of their starting body weight, depending on the dose. Results were also dose-dependent, and the group that lost the most weight (11.2%) received the maximum studied dose.

• In a different 36-week trial of Foundayo, participants lost, on average, 9%–15% of their body weight. For comparison, some people enrolled in the 72-week trial lost up to about 12% by week 36.

Foundayo and Zepbound work similarly to support weight loss. They’re both GLP-1 medications, but Zepbound packs more punch because it’s a GLP-1 and GIP medication.

Foundayo

Orforglipron, the active ingredient in Foundayo, is a glucagon-like peptide-1 (GLP-1) receptor agonist. By mimicking the GLP-1 hormone, Foundayo helps you lose weight by:

• Slowing stomach emptying, so you get full fast and stay full longer

• Reducing appetite and cravings, so you eat less 

• Increasing insulin release, so your blood sugar stays more stable

Zepbound

Tirzepatide, the active ingredient in Zepbound, targets two gut hormones: GLP-1 and glucose-dependent insulinotropic polypeptide (GIP). 

By mimicking both GLP-1 and GIP, Zepbound is able to do everything Foundayo does in the body and then some. More specifically, it can also help regulate metabolism by affecting the brain and fat tissue.

Foundayo is a daily pill, and Zepbound is a weekly injection. 

More specifically: 

• Take one tablet of Foundayo by mouth at the same time each day, with or without food, drinks, or other medications. 

• Inject Zepbound subcutaneously (under the skin) on the same day each week. You should rotate the injection site weekly between the abdomen, thigh, and upper arm. 

Absorption

Compared to Zepbound, Foundayo has a lower bioavailability — i.e. how much of the active ingredient is available in your bloodstream. This is because GLP-1s are absorbed less efficiently by the gastrointestinal tract when taken orally compared to when injected under the skin. 

• Zepbound has a high bioavailability of about 80%. 

• Foundayo has a bioavailability of about 20%–40%. 

FYI, the same explanation can be given when comparing the Wegovy pill vs. injection. 

Foundayo and Zepbound have different dosage strengths and schedules. Both medications start at a low dose, which is gradually increased (titrated) as the body adjusts to the medication. The goal is to ultimately find a maintenance dose of the drug that delivers desired results without too many side effects. 

• Foundayo is taken daily and comes in six dosage strengths: 0.8 mg, 2.5 mg, 5.5 mg, 9 mg, 14.5 mg, and 17.2 mg. The recommended maintenance dosage is 5.5 mg, 9 mg, 14.5 mg, or 17.2 mg, depending on your response to the medication. 

• Zepbound is administered weekly and comes in six dosage strengths: 2.5 mg, 5 mg, 7.5 mg, 10 mg, 12.5 mg, and 15 mg. The recommended maintenance dosage is 5 mg, 10 mg, or 15 mg, depending on your response to the medication.  

A typical dosage titration schedule for Foundayo and Zepbound might look like this:

**One-month intervals are for illustrative purposes. Foundayo dosage may be increased every 30 days, and Zepbound dosage may be increased every four weeks (28 days).

Never change your Foundayo or Zepbound dose without consulting your prescriber. If you’re experiencing unpleasant side effects, tell your provider, as dose increases can be delayed to allow your body to adjust. Some people may take longer to reach a maintenance dose than others.

As GLP-1 medications, Foundayo and Zepbound share many of the same side effects, most of which are gastrointestinal. 

Common Foundayo and Zepbound side effects include:

• Nausea

• Diarrhea

• Constipation

• Vomiting

• Burping and flatulence (gas)

• Heartburn

• Upset stomach

• Headaches

• Fatigue

• Hair loss

Because it’s a shot, Zepbound can also cause injection site reactions.

Though not common, serious side effects and risks of both drugs include:

• Kidney, gallbladder, or pancreas problems

• Diabetes-related vision changes

• Hypoglycemia (low blood sugar)

• Severe gastrointestinal reactions

• Allergic reactions

• Pulmonary aspiration during general anesthesia or deep sedation

Finally, all GLP-1s, including Foundayo and Zepbound, carry a strong warning about thyroid tumors. This is due to results from animal studies. One large study found that people taking GLP-1s didn’t have an increased risk of thyroid cancer compared to those taking other (diabetes) medications overall. But there was an increased risk of new thyroid cancer diagnosis in the first year of taking a GLP-1. So, while the overall risk is low, people with a personal or family history of thyroid cancer should not take Foundayo or Zepbound.

Without insurance or other discounts, Foundayo typically costs less than Zepbound.

Foundayo

Without insurance, Foundayo costs $149–$299 per month, depending on dose. This is with the manufacturer offer. Otherwise, 14.5 mg and 17.2 mg of Foundayo can be up to $349 per month — but that’s still less than the cash prices for the highest doses of Zepbound KwikPens. 

Here are the cash prices of Foundayo on Ro: 

• $149 per month: 0.8 mg dose

• $199 per month: 2.5 mg dose

• $299 per month: 5.5 mg and 9 mg doses 

• $299 per month: 14.5 mg and 17.2 mg doses (with manufacturer offer)

With insurance, Foundayo can cost just $25 per month with Eli Lilly’s Foundayo Savings Offer. To be eligible for this discount, you must have commercial health insurance with coverage for Foundayo and meet other requirements (such as being a resident of the US or Puerto Rico, among others).  

In July 2026, eligible Medicare Part D enrollees may be able to get Foundayo for $50 per month.

Zepbound

Without insurance, Zepbound can cost anywhere from $299 to over $1,000 per month, depending on the dosage strength, pharmacy used, and form (e.g. single-dose pen, single-dose vials, or multi-dose KwikPen).

While Zepbound has a list price of $1,086.37, Zepbound KwikPens and vials have the following cash prices on Ro: 

• $299 per month: 2.5 mg dose

• $399 per month: 5 mg dose 

• $449 per month: 7.5 mg, 10 mg, 12.5 mg, and 15 mg doses (with manufacturer offer)

Similar to Foundayo, the highest doses of the drug are available with a manufacturer offer that requires you to refill your Rx within 45 days of your previous fill. If you don’t, the cash price increases to $449 for the 7.5 mg dose and $699 for the 10 mg, 12.5 mg, and 15 mg doses. 

With insurance, Zepbound can cost as little as $25 per month with Eli Lilly’s official savings program. You must at least have commercial health insurance that covers Zepbound to qualify for this discount. 

There are some key factors to discuss with your healthcare provider when comparing and ultimately choosing Foundayo vs. Zepbound   (and ultimately deciding between Foundayo vs. Zepbound:

1. Your weight loss goals. If you’re hoping to lose a lot of weight, you might prefer Zepbound vs. Foundayo. While both drugs support weight loss, data from separate clinical trials show that Zepbound drives more weight loss than Foundayo.

2. Your comfort with injections. Zepbound might be more effective for weight loss, but it also involves weekly injections. If you’re not comfortable with that, an oral GLP-1 like Foundayo (or the Wegovy pill) might be a better fit. 

3. Your lifestyle. Are you more likely to stick to daily or once-weekly dosing? Some people prefer the routine of taking a daily pill with breakfast, while others like the flexibility of thinking about their weight loss medication just once a week. 

4. Other medical conditions. Remember, Zepbound is also approved to treat obstructive sleep apnea (OSA). If you have OSA and want to use a GLP-1 for weight loss, you may have a better chance of getting insurance coverage for Zepbound. 

5. Your insurance and budget. For many, the deciding factor comes down to the cost and which medication your insurance covers. 

Get started

When comparing Foundayo vs. Zepbound (or orforglirpron vs. tirzepatide, their active ingredients), it’s important to remember that they’re both effective for weight loss. Here’s the recap on what sets them apart:

• Both Zepbound and Foundayo are FDA-approved for weight loss and management in adults with obesity or overweight and at least one weight-related medication condition. Zepbound is also approved for OSA. 

• They work similarly. While both are considered members of the GLP-1 drug class, Zepbound is technically a GLP-1/GIP dual agonist.

• Because it targets two gut hormones (vs. Foundayo’s one), Zepbound has been shown to be more effective for weight loss, producing ~15%--22% weight loss in 72 weeks. Foundayo, on the other hand, can lead to up to 11.2% weight loss in the same time period. 

• Side effects are similar. They’re both known to cause gastrointestinal side effects, such as nausea, constipation, diarrhea, and vomiting. 

• Dosing frequency and administration differ. Foundayo is taken by mouth daily, whereas Zepbound is injected once a week.

• Without insurance, Foundayo costs less than Zepbound. The weight loss pill has a cash price of $149–$299 (with manufacturer offer), depending on the dose. Zepbound KwikPens and vials have a cash price of $299–$449 per month, depending on the dose.