Is Ozempic or Phentermine better for weight loss?

Only Ozempic has a trial figure recorded here: 6.4% average weight loss, worked out from the kilograms on its label. Phentermine has none on this site, so the two cannot be compared on effect and this page does not pick one on it.

Which is cheaper, Ozempic or Phentermine?

Phentermine publishes no all-in monthly price that could be verified, so this page carries no comparison rather than an estimate — and an unpublished price is itself worth weighing.

Can you switch between Ozempic and Phentermine?

They are different molecules, so this is a change of medication rather than of brand, and the one you move to is started on its own dosing schedule.

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Ozempic (semaglutide, diabetes label) vs Phentermine (generic)

Verdict

Neither comes out ahead on the axes compared here. Ozempic scores higher on the published halfrx formula, 5.1 against 3.1; the formula takes in more than this table does.

Computed from the stored fields, so it moves when a price does. Nothing here is written by hand or by a model.

Ozempic (semaglutide, diabetes label) or Phentermine (generic): which one has a price?

Only Ozempic (semaglutide, diabetes label) has an all-in figure here: $199–$499 a month, read from its own page on 2026-09-22. No price is published here for Phentermine (generic), so price cannot decide between them. Every axis below is computed from stored fields rather than written by hand, so the comparison moves when a price does. Neither carries an FTC action, a state action, a BBB F grade or an FDA warning letter. One is branded and the other generic, and they are different drugs, so the gap is the molecule as well as the price. The published formula scores them 5.1 and 3.1 out of 10, arithmetic over the same stored fields rather than an editor's preference. Cost here is scored on what a patient pays once titrated, never on the entry price, because an introductory rate covers the months before anybody has reached the dose they stay on.

Head to head

Ozempic (semaglutide, diabetes label) against Phentermine (generic), one row per axis, with the side that wins each axis marked.
What decides it	Ozempic $199–$499/mo	Phentermine price unverified
Entry priceNot comparable — Phentermine (generic) publishes no verified all-in price.	not comparable	not comparable
Regulatory and complaint riskNeither carries a lawsuit, an FDA warning letter or a supply-risk flag.	tied	tied

What the trials, the titration and a year actually say

Axis	Ozempic	Phentermine
The trial that figure comes from	No percentage of body weight appears anywhere on the Ozempic label, which has no weight-management section: its three trial sections cover glycemic control, cardiovascular outcomes and kidney outcomes, and all report weight in kilograms. This figure is worked out from the label's own kilograms — 6.4 kg lost from a 100.1 kg mean baseline at week 40 on 2 mg — and is an arithmetic step the label does not take.	The label does not carry a modern trial figure; it states in its own words that the usefulness of this class 'should be measured against possible risk factors', and it is not recommended for long-term use.
Maintenance dose	0.5 mg to 2 mg once weekly	37.5 mg once daily, in the morning
Earliest week you reach it	week 5	—
Year one at the published price of every step	$4,237	No titration prices recorded

The year-one figures walk each titration step at its published price and count the thirteen fills a 28-day month bills. The full arithmetic is published.

Go to Ozempic ↗Go to Phentermine ↗

What separates these two, price aside

These are different molecules — semaglutide against phentermine — so this is a comparison of two treatments, not of two prices for one.

Novo Nordisk

Ozempic (semaglutide, diabetes label)

5.1

$199–$499/mo all-in

verified 2026-09-22

Off-label for weightBoxed warning

Multiple generic manufacturers

Phentermine (generic)

3.1

Price unverified

Controlled substanceWeaker moleculeNo published priceStrict dosing rules

Ozempic (semaglutide, diabetes label)

Pros

+New self-pay patients pay $199 for the first two monthly fills on TrumpRx, through 31 December 2026, then $349 a month at 0.25 to 1 mg.[2]
+Identical active molecule to Wegovy.[2]
+If you have type 2 diabetes, this is the on-label product and the one insurance is most likely to cover.[2]

Cons

−Using it for weight loss without diabetes is off-label. Insurers deny it on that basis and prescribers vary in willingness.[2]
−Its top dose is 2 mg, against 2.4 mg for standard Wegovy and 7.2 mg for Wegovy HD; the Ozempic label reports no weight-loss percentage to set beside Wegovy's.[5]
−Prescribing it off-label for weight competes with diabetes patients for supply — a recurring shortage driver.[2]

Sources

Phentermine (generic)

Pros

+Pharmacies acquire it at $0.068 a tablet, about $2 for a 30-day supply, under the federal NADAC survey. That is what a pharmacy pays, not what it charges you.[2]
+Covered by more Medicaid programs than any GLP-1 — seven states cover an older weight-loss agent while covering no GLP-1 at all.[3]
+One tablet each morning, no injection, no titration schedule beyond a possible half dose.[1]

Cons

−Approved for a few weeks only. Every monthly subscription selling it as ongoing therapy is using it off the label's own duration.[1]
−Schedule IV controlled substance, chemically related to the amphetamines, with the dependence warnings that follow from that.[1]
−Stopping after prolonged high dosing brings extreme fatigue and depression, per the label — which is a hard exit from a subscription that sold it as maintenance.[1]
−No cardiovascular outcome data of the kind the GLP-1s now carry, and contraindicated where blood pressure is uncontrolled.[1]

Sources

Ozempic side effects →Phentermine side effects →Ozempic dosage →Phentermine dosage →

Comparisons are computed from the fields on each card, not written by hand or by a model, so they change when the data does. Information only, not medical advice. halfrx may earn a commission from some links, which never changes what a comparison says.

Everything on Ozempic

Everything on Phentermine

Ozempic against Phentermine, answered

Is Ozempic or Phentermine better for weight loss?: Only Ozempic has a trial figure recorded here: 6.4% average weight loss, worked out from the kilograms on its label. Phentermine has none on this site, so the two cannot be compared on effect and this page does not pick one on it.
Which is cheaper, Ozempic or Phentermine?: Phentermine publishes no all-in monthly price that could be verified, so this page carries no comparison rather than an estimate — and an unpublished price is itself worth weighing.
Can you switch between Ozempic and Phentermine?: They are different molecules, so this is a change of medication rather than of brand, and the one you move to is started on its own dosing schedule.