An area gaining increasing attention in both conventional and integrative medicine is the role of incretins, especially glucagon-like peptide-1 (GLP-1) – a powerful hormone with widespread metabolic benefits.

What Are Incretins?

Incretins are a group of gut-derived hormones secreted in response to food intake. The two classical incretins are glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). These hormones stimulate insulin secretion in a glucose-dependent manner, meaning that they help lower blood sugar and reduce appetite without significantly increasing the risk of hypoglycaemia. GLP-1 plays a key role in glucose metabolism, making it a target for many diabetic and weight loss drugs.^1-3

Other peptide hormones such as leptin, ghrelin, peptide YY (PYY), and cholecystokinin (CCK) regulate appetite^4,5 but are not classified as incretins.

What are the GLP-1 Drugs Everyone’s Talking About?

The GLP-1 drugs making headlines, semaglutide (Ozempic, Wegovy), liraglutide (Saxenda, Victoza) and dulaglutide (Trulicity), are GLP-1 receptor agonists. These medications mimic the action of GLP-1. You may have also heard of tirzepatide (Mounjaro, Zepbound). This is a ‘twincretin’ – a medication that acts as a dual agonist for both GLP-1 and GIP receptors. By binding to GLP-1 receptors in the pancreas, stomach, brain, and heart these drugs enhance glucose-dependent insulin secretion, decrease inappropriate glucagon release, slow gastric emptying, and improve satiety, leading to improved glycaemic control and clinically significant weight loss.^6-8

Figure 1. GLP-1 Actions in Peripheral Tissues⁹

NB: GLP-1 acts directly on the pancreas, stomach, brain, and heart, whereas actions on the liver, fat and muscle tissue are indirect.^9,10

A meta-analysis highlights that long-acting GLP-1 receptor agonists – particularly semaglutide and tirzepatide – achieve slightly better glycaemic control (glycated haemoglobin [HbA1c] reduction) in patients with type 2 diabetes mellitus (T2DM), compared to basal insulin treatment. These GLP-1 receptor agonists also provide added benefits such as weight loss, reduced hypoglycaemia risk, lower blood pressure, and improved lipid profiles.¹¹

However, GLP-1 medications are associated with more gastrointestinal tract (GIT) side effects. The meta-analysis reported that medication discontinuation rates were 60% to 71% higher, compared to basal insulin.¹¹

While the overall benefit-risk relationship is favourable for most patients, caution is advised in those with advanced comorbidities.¹¹

Natural Ways to Support Incretin Function

Pharmaceutical drugs underscore the therapeutic potential of GLP-1 – something naturopaths can help support naturally through targeted herbal medicine, and diet and lifestyle changes.

Herbs

Bitter compounds, like those found in Gentian, can modulate gut hormones and slow gastric emptying, helping to regulate food intake.¹² Other herbs that may stimulate GLP-1 secretion include Bitter Melon,^13,14 Hops,¹⁵ Andrographis,¹⁶ and berberine-containing herbs.^17-19

Diet

Reduce energy intake: in vivo evidence suggests that lead-in calorie restriction before commencing incretin-based therapy enhances weight loss.²⁰

Dietary fibre: dietary fibre reduces hunger and prolongs satiety by stimulating the release of incretins from enteroendocrine cells, gastric distension (bulking effect) and delayed gastric emptying, and improving postprandial glycaemic control. The fermentation of fibres by intestinal microflora produces short-chain fatty acids (SCFAs) which also stimulates the secretion of GLP-1 and peptide YY (PYY). Furthermore, meals containing more fibre require more chewing. This slowing down is also thought to contribute to increased satiety signals.²¹

Polyphenols: preclinical evidence shows that curcumin (Turmeric), epigallocatechin gallate (EGCG) [Green Tea], silymarin (St Mary’s Thistle),²² and resveratrol (grapes, peanuts and berries),²³ among other polyphenols, induce GLP-1 secretion. A trial in healthy individuals showed that oleuropein (Olive Leaves) [20 mg] significantly improved postprandial glycaemia, i.e., increased insulin and GLP-1, and decreased blood glucose and dipeptidyl peptidase 4 (DPP-4)²⁴ – an enzyme that inactivates GLP-1 and GIP.²⁵

High-protein breakfast: starting the day with a high-protein meal (i.e. 60% of energy from protein) can increase GLP-1 and PYY levels, relative to high fat or high carbohydrate breakfasts.²⁶

Avoid ultra-processed foods: consuming ultra-processed foods may disrupt appetite regulation by altering gut-brain axis signalling and modulating ghrelin, GLP-1, GIP, and PYY levels; and increase hedonic appetite by promoting faster eating rates, enhancing palatability, activating brain reward circuits, and potentially increasing food addiction behaviours.²⁷

Lifestyle

Exercise: exercise may help to counter the GLP-1 resistance seen in patients with T2DM. The combination of GLP-1-based therapy and exercise may therefore have a synergistic effect.²⁸ Results of a systematic review (nine clinical trials, n=4236) show that the combination of liraglutide and exercise led to an average weight loss of 5 kg over 53 weeks in those with obesity.²⁹ Note that excess visceral fat and gut dysbiosis contribute to GLP-1 resistance in obesity (with a high degree of insulin resistance) and T2DM.²⁸ Overall, the benefits of physical activity/exercise in T2DM³⁰ and obesity³¹ cannot be overstated.

Where to from Here for Practitioners?

Incretins, particularly GLP-1, represent a fascinating intersection between the gut, brain and metabolism. By harnessing naturopathic tools, clinicians can help patients optimise their incretin response naturally, potentially improving not just glycaemic control but also their cardiometabolic and neurological health.

But even as science continues to evolve, the message will almost certainly remain the same, aligning with what we so often already tell our patients: supporting GLP-1 and weight loss is about much more than blood sugar. As with every condition, it’s about fostering whole-person resilience.

If this article has whet your appetite to learn more about incretins, please register for Integria Practitioner’s 2026 Symposium, The Incretin Revolution: Natural Medicine’s Role in Forging Tomorrow’s Healthcare, at practitioner.integria.com/events/ipsym26

References

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