Has anyone compared Foundayo and Qsymia in the same trial?

No head-to-head trial has compared these two drugs. Foundayo's figures come from ATTAIN-1 (72 weeks) and Qsymia's from CONQUER (56 weeks), which enrolled different people for different lengths of time. Numbers from separate trials can be read side by side, but they are not a measured difference.

What does each one cost per month?

Foundayo is listed at $149–$349/month. Qsymia is listed at $30–$400/month (generic; brand runs to $400). The full price note for each is set out in the cost section above. What you pay depends on your insurance, your dose and your pharmacy.

Can I switch from Foundayo to Qsymia?

Switching between weight-loss medicines is a decision for the prescriber who knows your history, your other medicines and how you have responded so far — this site cannot make it for you. What switching involves in practice, including dose steps and the gap between drugs, is set out on the switching page.

Which side effects were reported most often?

In ATTAIN-1 (72 weeks), the reaction reported most often with orforglipron was nausea — 33% of participants. In CONQUER (56 weeks), the reaction reported most often with phentermine / topiramate ER was dry mouth — 21% of participants. Rates come from different trials with different participants, and a rate is not a prediction for any one person.

Foundayo vs Qsymia: trials compared

At a glance

Foundayo and Qsymia compared on form, trial results, cost and reported side effects
	Foundayo	Qsymia
Form	Daily pill	Daily capsule
How often	Once-daily pill — no injection, no fasting, no food timing	Daily oral capsule — no injection
Weight loss in trials	Up to 12.4% — ATTAIN-1 (72 weeks)	Up to 9.8% — CONQUER (56 weeks)
FDA approved	2026	2012
Made by	Eli Lilly	Vivus
How it works	A small-molecule (non-peptide) GLP-1 receptor agonist.	Phentermine suppresses appetite by triggering the release of adrenaline-like chemicals in the brain's hunger control centre.
Monthly cost, self-pay	$149–$349/mo	$30–$400/mogeneric; brand runs to $400
Most reported reaction	Nausea 33% (ATTAIN-1)	Dry mouth 21% (CONQUER)

Every figure in this table is read from the same trial and label records used everywhere else on this site.

Weight loss at the highest dose in each trial

No head-to-head trial has compared these two drugs.

Foundayo(orforglipron)12.4%

ATTAIN-1 (72 weeks)

Qsymia(phentermine / topiramate ER)9.8%

CONQUER (56 weeks)

In clinical trials, participants taking orforglipron lost on average up to 12.4% of their starting body weight, and participants taking phentermine / topiramate ER lost on average up to 9.8%. Those numbers come from two different studies: ATTAIN-1 enrolled 3,127 adults with obesity or overweight with comorbidities, no type 2 diabetes over 72 weeks against placebo, while CONQUER enrolled 2,487 adults with obesity and at least 2 weight-related health conditions over 56 weeks against placebo. Who took part, how long each trial ran and what each drug was measured against all move the percentage, so the two figures are not a measured difference between the drugs.

Monthly cost, self-pay

The bar spans the range in each drug's price record — lowest listed price to highest.

Foundayo$149–$349/mo

$149/month self-pay at the lowest dose, up to $349/month at the highest dose via LillyDirect. $25/month with the commercial insurance savings card. Medicare Part D coverage expected from July 2026 at ~$50/month.

Qsymia$30–$400/mo

generic; brand runs to $400

~$30–$80/month generic; ~$200–$400/month brand (Qsymia).

Self-pay prices are what the manufacturer or the pharmacy lists, not what most people end up paying. Foundayo: $149–$349/month. Qsymia: $30–$400/month. Insurance, dose and pharmacy all change both figures.

Side effects reported in the trials

Both trials reported one reaction in common. Each rate is the percentage of participants who reported it in the trial named beside it, so the two columns are not from the same study.

Constipation

Foundayo · ATTAIN-118%

Qsymia · CONQUER17%

A rate is the share of trial participants who reported that reaction, not a prediction for any one person.

How they differ in practice

How you take it

Foundayo — Once-daily oral tablet. No food or water restrictions.
Qsymia — Once-daily extended-release capsule

Dose build-up

Foundayo — 3 mg → 6 mg → 12 mg → 36 mg, escalated over several months
Qsymia — 3.75/23 mg → 15/92 mg, titrated over 14 weeks

Where a drug is not listed here, its prescribing information sets out its own dose steps.

How soon it acts

Foundayo — Appetite changes typically within the first 4 weeks; meaningful weight loss by 12–16 weeks
Qsymia — Appetite suppression typically begins within the first week; significant weight loss by 12–16 weeks

Heart and metabolic findings

Foundayo — Cardiovascular outcomes data pending.
Qsymia — In CONQUER, significant reductions in blood pressure, waist circumference, triglycerides, and blood glucose were observed.

As stated in each drug’s trial record — not a claim about which drug protects the heart more.

Other findings recorded

Foundayo — No food or water restrictions — take any time of day; available at $149/month self-pay (lowest dose) or $25/month with commercial insurance
Qsymia — Generic now available (from 2025) — significantly lower cost than GLP-1 drugs; improved blood pressure and triglycerides in CONQUER trial

If you stop taking it

Foundayo — No withdrawal trial has been published for Foundayo.
Qsymia — Weight regain after stopping is expected.

Common questions

Written and maintained by one person · Built with agentic AI tools · Every number checked against the cited trial · Not medical advice

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Foundayo in full

Foundayo — results, side effects, cost and how it is taken

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Qsymia — results, side effects, cost and how it is taken

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Last reviewed: September 2026

Medical disclaimer: This website is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting, stopping, or changing any treatment.