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August 18, 2026 · Side-by-side comparison authority

GLP-1 vs Old-School Phentermine: The 2026 Comparison

Phentermine has been prescribed for weight loss for over 60 years. GLP-1s represent the current generation. The two work through completely different mechanisms with dramatically different efficacy, safety, and use profiles. Here's the direct comparison.

The Comparison Table

AttributePhentermineGLP-1 (semaglutide/tirzepatide)
Drug classSympathomimetic amineGLP-1 receptor agonist
MechanismAppetite suppression via CNSMultiple metabolic pathways
Typical weight loss5-10%15-20%
FDA approval scopeShort-term (12 weeks)Chronic weight management
Approx monthly cost$10-$40 generic$199-$449 brand cash-pay
CV outcome evidenceNone (predates modern trials)Positive (SELECT, SURMOUNT-MMO)

Where Phentermine Still Has a Niche

Phentermine remains a legitimate short-term option for patients who: can't afford GLP-1s and have no coverage, need short-term appetite suppression for a specific goal, have contraindications to GLP-1s, or have tried GLP-1s without response and are looking for alternatives. Generic phentermine is cheap and accessible.

The FDA-approved indication is short-term (12 weeks), though off-label longer-term use has been common in bariatric medicine for decades. The safety profile of longer-term use is less thoroughly characterized than modern chronic-management options.

Oak Weight Loss

GLP-1 program

Telehealth program with compounded GLP-1 access.

  • Compounded GLP-1
  • Standard intake
  • Membership pricing
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

Why GLP-1s Have Largely Superseded Phentermine

GLP-1s produce greater weight loss magnitude, are approved for chronic use, have established cardiovascular outcome evidence, and have kidney and heart failure outcome data. Phentermine has none of these. For patients who can access GLP-1 therapy through insurance or cash-pay, GLP-1s are the more effective and more evidence-supported choice.

Found Health

$100 off promo

Brand-name GLP-1 access with coaching layer.

  • Brand-name focus
  • Coaching + accountability
  • Insurance-coordinated
Check Latest Pricing

Sesame Care

Brand-name pathways

Marketplace for brand-name FDA-approved GLP-1 only.

  • Brand-name only
  • Direct consult marketplace
  • Cash-pay clarity
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Combination Approaches

Some prescribers combine phentermine with GLP-1 therapy for additive appetite suppression, particularly in patients with insufficient GLP-1 response or during titration periods. The combination isn't standard and requires prescriber judgment about safety in the individual patient.

Embody

Injectable semaglutide, $400 CPA tier

Injectable semaglutide only — lead compounded option.

  • Injectable semaglutide focus
  • Standard titration
  • Direct pharmacy shipping
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

Wellorithm

Sema ~$147/mo, tirz ~$249/mo

Compounded GLP-1 with dose-tier pricing.

  • Sema and tirz options
  • Tier pricing by dose
  • Verify at intake
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

The 2026 Framing

Phentermine is the affordable, short-term, older option. GLP-1s are the more effective, more expensive, chronic-management option. For patients with access, GLP-1s are the modern first-line. For patients without access, phentermine remains an option worth discussing with a prescriber — but with clear understanding of the efficacy and evidence differences.

MadeMed

Compounded GLP-1 options

Independent compounder — sema, tirz, and oral formats.

  • Compounded sema/tirz
  • Oral tirz $167-229
  • Direct pharmacy fulfillment
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

Telos Rx

Compounded tirzepatide

Compounded tirzepatide via direct pharmacy.

  • Compounded tirzepatide
  • Direct-link intake
  • Verify pricing
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

Where to Start

Embody

Injectable semaglutide, $400 CPA tier

Injectable semaglutide only — lead compounded option.

  • Injectable semaglutide focus
  • Standard titration
  • Direct pharmacy shipping
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

Wellorithm

Sema ~$147/mo, tirz ~$249/mo

Compounded GLP-1 with dose-tier pricing.

  • Sema and tirz options
  • Tier pricing by dose
  • Verify at intake
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing

MadeMed

Compounded GLP-1 options

Independent compounder — sema, tirz, and oral formats.

  • Compounded sema/tirz
  • Oral tirz $167-229
  • Direct pharmacy fulfillment
FDA note: Compounded GLP-1 medications are not FDA-approved. Personalization must be based on a documented clinical need per current FDA guidance.
Check Latest Pricing
Medical & editorial disclaimer. This article is for informational purposes only and is not medical advice. GLP-1 medications require prescriber evaluation. Compounded GLP-1 medications are not FDA-approved. Talk to a licensed clinician before starting, stopping, or changing any prescription. Provider pricing, availability, and program terms change frequently — verify current details on each provider's site before making a decision. Some links are affiliate links, which means we may earn a commission if you sign up; this does not change our recommendations or the price you pay.