Semaglutide tablets: everything you need to know about oral treatment

Semaglutide tablets are marketed as Rybelsus and represent a significant advance in diabetes treatment as the first oral GLP-1 receptor agonist.

Background:

GLP-1 receptor agonists have traditionally been available only as injectable medicines because peptide molecules are broken down in the digestive tract.

Oral semaglutide overcomes this barrier through a co-formulation with salcaprozate sodium (SNAC), an absorption enhancer that protects semaglutide from degradation in the stomach and facilitates its absorption through the gastric lining.

Available strengths:

• 3 mg: the starting dose, used for the first 30 days
• 7 mg: the intermediate dose, which may be a maintenance dose for some patients
• 14 mg: the full maintenance dose, providing the greatest efficacy

Licensed indication:

Rybelsus is licensed in the UK for the treatment of adults with insufficiently controlled type 2 diabetes as an adjunct to diet and exercise.

It can be used as monotherapy when metformin is not tolerated, or in combination with other glucose-lowering medicines.

Important distinction:

Oral semaglutide (Rybelsus) is licensed only for type 2 diabetes, not for weight management.

Injectable semaglutide is available as Ozempic (for diabetes) and Wegovy (for weight management). They are not interchangeable.

The way you take Rybelsus is critical to its absorption. Unlike most oral medicines, it has very specific administration requirements.

Step-by-step instructions:

• Take the tablet first thing in the morning on a completely empty stomach
• Swallow the tablet whole with no more than 120 mL (half a glass) of plain water
• Do not crush, chew or split the tablet, as this destroys the SNAC absorption mechanism
• Wait at least 30 minutes before eating, drinking anything else or taking other oral medicines
• Take only one tablet per day

Why these rules matter:

The SNAC enhancer works by creating a localised increase in pH on the stomach wall, allowing semaglutide to be absorbed transcellularly.

Food, large volumes of liquid or other medicines in the stomach interfere with this process and dramatically reduce absorption.

Studies show that bioavailability drops by approximately 40% if the tablet is taken with food.

Common mistakes to avoid:

• Taking the tablet with a full glass of water or other drinks
• Eating within 30 minutes of taking the tablet
• Taking other medicines (including antacids or proton pump inhibitors) at the same time
• Splitting the tablet to adjust the dose

The BNF emphasises that patients must be clearly counselled on the correct administration to ensure the medicine works effectively.

If you struggle with the fasting requirement, discuss this with your prescriber.

The efficacy of oral semaglutide has been established in the PIONEER trial programme, which included over 9,000 patients with type 2 diabetes.

HbA1c reduction:

• PIONEER 1 (monotherapy): oral semaglutide 14 mg reduced HbA1c by 1.5 percentage points at 26 weeks versus 0.0 with placebo
• PIONEER 2 (vs empagliflozin): oral semaglutide 14 mg was superior to empagliflozin 25 mg at 26 weeks
• PIONEER 4 (vs liraglutide): oral semaglutide 14 mg was non-inferior to liraglutide 1.8 mg at 26 weeks and superior at 52 weeks

Weight loss:

• Oral semaglutide 14 mg produces approximately 4 to 5 kg weight loss on average in diabetes trials
• This is less than injectable semaglutide (Ozempic 1 mg typically produces 5 to 7 kg) due to lower bioavailability

Comparison with injectable semaglutide:

• PIONEER 7 allowed flexible dosing of oral semaglutide versus injectable semaglutide 0.5 mg. The oral formulation was non-inferior for HbA1c reduction
• Overall, oral semaglutide 14 mg is considered broadly comparable to injectable semaglutide 0.5 mg in terms of glycaemic efficacy
• Injectable semaglutide 1 mg and 2 mg are more potent than the oral form

NICE technology appraisals support the use of oral semaglutide as part of the treatment pathway for type 2 diabetes when other agents are insufficient.

The side effect profile of oral semaglutide is similar to that of injectable GLP-1 agonists, with gastrointestinal effects predominating.

Very common (more than 1 in 10 people):

• Nausea: the most reported side effect, affecting approximately 16 to 20% of patients on the 14 mg dose. Usually worst during dose escalation
• Diarrhoea: reported by approximately 10% of patients

Common (1 in 10 to 1 in 100 people):

• Reduced appetite: contributes to weight loss
• Vomiting: usually transient
• Abdominal pain and bloating
• Constipation
• Dyspepsia and gastro-oesophageal reflux
• Flatulence

Serious but rare:

• Pancreatitis: seek immediate medical advice for severe, persistent abdominal pain
• Diabetic retinopathy complications: rapid improvement in blood sugar control can sometimes worsen pre-existing diabetic eye disease. NICE recommends eye screening before and after starting treatment in patients with known retinopathy
• Gallbladder events: gallstones and cholecystitis, particularly with weight loss

Hypoglycaemia:

When used alone or with metformin, the risk of hypoglycaemia is low. However, if combined with insulin or sulphonylureas, dose reductions of the other medicine may be needed to avoid low blood sugar.

The BNF advises that patients should be counselled on the signs of pancreatitis and instructed to stop the medicine and seek medical review if symptoms develop.

Oral semaglutide may be particularly suitable for certain groups of patients with type 2 diabetes.

Ideal candidates:

• Patients who prefer not to have injections or have needle phobia
• Those who have not achieved target HbA1c with metformin alone or in combination with other oral agents
• Patients who would benefit from modest weight loss alongside glucose control
• Those who can reliably follow the specific administration instructions each morning

Patients who may not be suitable:

• Those with gastroparesis or severe gastrointestinal disease: the slowing of gastric emptying may worsen symptoms
• Patients with a history of pancreatitis: GLP-1 agonists carry a rare risk of pancreatitis
• Those unable to follow fasting instructions: erratic administration significantly reduces efficacy
• Pregnant or breastfeeding women: semaglutide should be stopped at least 2 months before a planned pregnancy
• Patients with type 1 diabetes or diabetic ketoacidosis: GLP-1 agonists are not indicated

Switching from injectable to oral semaglutide:

Patients on injectable semaglutide (Ozempic) may wish to switch to tablets.

The day after the last injection, oral semaglutide can be started, though the prescriber should be aware that the oral form may be less potent than the injectable equivalent.

NICE positions oral semaglutide alongside injectable GLP-1 agonists and SGLT2 inhibitors in the type 2 diabetes treatment pathway, typically after metformin and lifestyle measures have proved insufficient.

Making oral semaglutide part of your daily routine requires some planning, but most patients adapt quickly.

Building a morning routine:

• Set an alarm 30 to 45 minutes before you normally eat breakfast
• Keep the tablets and a small glass on your bedside table
• Take the tablet as soon as you wake up, before getting out of bed if you wish
• Use the 30-minute waiting period for your morning routine: showering, getting dressed, preparing breakfast

Managing the fasting window:

• If you are an early riser who eats breakfast at 6am, take the tablet at 5:30am
• If you normally skip breakfast, you have more flexibility with timing
• Do not take other medicines during the 30-minute window; move them to after breakfast

What to do if you miss a dose:

• If you miss a day, skip that dose and take the next one as usual the following morning
• Do not take two tablets on the same day to make up for a missed dose
• If you miss several days, contact your prescriber for advice

Storage:

• Store tablets in the original blister pack to protect from moisture
• Keep below 30 degrees Celsius
• Do not remove a tablet from the blister until ready to take it

Monitoring:

• Regular HbA1c checks (every 3 to 6 months) will confirm whether the medicine is working
• Blood pressure, weight and kidney function should be monitored at review appointments
• Report any persistent gastrointestinal symptoms that do not improve after the first few weeks