Oral vs Injectable Weight Loss Medications

Weight loss medicines can be taken as daily tablets or weekly injections. Both forms can be effective, but they work in slightly different ways and suit different preferences or lifestyles.

Oral medicines such as Rybelsus (oral semaglutide) offer convenience and avoid needles but require strict timing and need to be taken on an empty stomach. Injectable treatments like Wegovy, Saxenda, and Mounjaro deliver steady absorption through the skin and are usually taken once a day or once a week.

The right choice depends on your medical history, comfort level, and how well your body absorbs and tolerates each form.

Both types act on the same hormone system (GLP-1), but the route of delivery affects how quickly and how much medicine reaches your bloodstream.

• Injectables: Deliver medicine directly under the skin for steady release.
• Tablets: Must pass through the stomach, so only a small amount is absorbed.
• Both reduce appetite, slow digestion, and help manage blood sugar—but injections are more potent because the body receives a consistent dose.

Injectable forms seem to show similar weight loss reductions as oral forms in studies. 

Injectable GLP-1

• Example brands: Wegovy, Saxenda

• Average weight loss: 10–15% (semaglutide / liraglutide)

• Frequency: Daily or weekly

• Key trials: STEP, SCALE

Injectable Dual GIP / GLP-1

• Example brands: Mounjaro

• Average weight loss: 15–22%

• Frequency: Weekly

• Key trials: SURMOUNT-1

Oral GLP-1

• Example brands: Rybelsus

• Average weight loss: ~20%

• Frequency: Daily

• Key trials: OASIS-4

Non-GLP-1 Oral (e.g. Orlistat)

• Example brands: Alli, Xenical

• Average weight loss: 5–10%

• Frequency: Daily

• Key trials: Cochrane 2017

Both versions share similar side effects such as nausea, reflux, and constipation. Injectables may cause mild injection-site irritation, while oral tablets can cause stomach upset if taken incorrectly.

Detail

• Injectables: nausea, fatigue, constipation, rare injection-site redness.
• Oral: nausea or burping if eaten too soon after dosing.
• Most side effects improve after the first few weeks.

Your choice depends on lifestyle, convenience, and personal comfort.

• Tablets: Best for those who prefer no injections and can manage daily timing and strict rules on taking it on an empty stomach.
• Injections: Ideal for those who prefer less frequent dosing and greater efficacy.
• Travel: Injectables require refrigeration before use; tablets are easier to store.
• Adherence: Weekly injections may improve consistency over daily tablets.

Costs vary, but weekly injections are typically more expensive and sometimes harder to obtain due to demand.

• Oral GLP-1: £120–£180 per month (private).
• Injectables: £150–£300 per month depending on brand and dose.
• NHS access: Currently very limited mainly to Wegovy in Tier 3 services.

Private prescribing available for eligible adults under medical supervision.

There’s no single “better” option—your clinician will match treatment to your health, goals, and preferences.

If you value convenience and dislike needles, oral Rybelsus may be suitable. If your goal is maximum weight loss or improved metabolic outcomes, injections like Wegovy or Mounjaro may be more effective. Many people eventually switch forms as their treatment plan evolves.

Dr Abby Hyams completed her medical training in Bristol and has been a GP for 19 years, spending many of those as a partner in an NHS practice in Hemel Hempstead. She has a particular passion for supporting patients with weight loss and promoting positive behaviour change, helping individuals build sustainable habits that improve their long-term health and wellbeing.

• Wilding JPH et al. N Engl J Med 2021 (STEP 1)
• Jastreboff AM et al. N Engl J Med 2022 (SURMOUNT-1)
• Davies M et al. Diabetes Care 2019 (PIONEER-4)
• Nauck MA et al. Diabetes Obes Metab 2021 (PIONEER-10)
• NICE NG248 (2023)
• EMA EPARs for Wegovy, Rybelsus, Mounjaro, Saxenda

This article is for general information only and should not be used for the diagnosis or treatment of medical conditions. Medic Spot Limited has used all reasonable care in compiling the information but makes no warranty as to its accuracy. Consult a doctor or other healthcare professional for diagnosis and treatment of medical conditions. In the event of an emergency, please call 999 for immediate assistance.

There is no guarantee of a specific weight loss medication being prescribed. Clinicians will review your online questionnaire alongside other independently validated medical information about you and will recommend the most appropriate weight loss treatments for you based on your answers. In some cases, the clinicians may contact you for additional information. See Terms of Service for more information.