GLP-1 taste effects: overview
- Evidence shows GLP-1 drugs can both reduce and enhance taste perception
- Study found 85% of users had weaker measured taste function
- Survey data suggests many users experience more intense flavours instead
- Sweetness most affected with both intensification and dulling reported frequently
- Food brands should prioritise balance, avoiding extremes to appeal broadly
GLP-1 weight-loss drugs are already reshaping the food sector.
Their main role has been reducing what is known as ‘food noise’ – essentially, the brain’s continual signal telling a person to eat, even when they’re full. But they also have been found to have a significant impact on taste.
GLP-1s tend to be seen as reducing or dulling taste, but some research has suggested that they may, in fact, enhance it.
GLP-1s dull taste – the evidence
The conventional wisdom is that GLP-1s dull taste, with significant research pointing in this direction.
GLP-1s significantly impair taste function, according to a study published last year.
Around 85% of GLP-1 users participating performed worse for taste perception than the controls who were not using the drugs. This impacted all five types of taste (sweet, bitter, umami, salty and sour).
Other factors, such as smoking or COVID-19 history, were found to have no relationship to taste perception.
Those who experienced side-effects of GLP-1s had better taste function than those who did not.
However, fewer than 25% of participants self-reported a decline in their own taste function. Furthermore, some reported being more sensitive to sweet or sour tastes, and more sensitive to food textures, although these were from answers to open-ended questions and not formally measured in the study.
Smell function was not significantly impacted, despite the key role of smell in taste.
Anecdotal reports elsewhere have also suggested that people taking GLP-1s taste food differently. Some have reported a metallic or dull taste when eating.
These changes may be due to the drugs’ direct impact on taste buds and receptors, as well as reduced saliva production, suggests Alan Marson, director of consultancy New Food Innovation.
However, some research suggests that the drugs can actually enhance taste.
Do GLP-1s actually enhance taste?
Some research suggests that GLP-1 is more likely to enhance taste than dull it.
A wide-ranging survey by market research company MMR Research interviewed 974 people in the UK, of whom 518 were currently using the drugs.
Just under half of users experienced a change in how they tasted food. The research found that they more commonly experienced more intense flavours, rather than less, when on GLP-1s.
The degree with which this happened varied depending on the taste. Nearly half of participants experienced more intense sweet flavours, for instance, while 37% experienced greater saltiness, 34% greater sourness and only 32% greater bitterness.
The impact on taste the other way – the dulling of taste – was also the greatest for sweetness, with 21% reporting sweetness being dulled when on the drugs.
The flavour that was impacted the least by GLP-1 use, according to the survey, was bitterness, which stayed the same for more than half of users. For saltiness and sourness, taste stayed the same for nearly half.
GLP-1 impact on taste is complex
In both cases, findings are nuanced. In the earlier study showing that taste perceptions were dulled by GLP-1s, some consumers self-reported that sensitivity to sweetness and sourness was enhanced. In MMR’s research, around a quarter of participants reported that the drugs dulled their taste perception.
For manufacturers, the focus should be on avoiding tastes that can put off GLP-1 consumers, rather than deciding to dull or intensify tastes across the board.
As research seems to converge on sweet tastes being made more intense, reducing sweetness seems to be the place to start. Brands must also focus on keeping non-users on board.
“Brands that dial down the extremes [in taste] may be better placed to protect the appeal amongst lower appetite consumers without alienating the mainstream,” says Andy Wardlaw, chief ideas officer at MMR Research. The popularity of GLP-1s, he says, suggests that food may move away from the maximalism that is currently popular.
In conclusion, there is no one-size-fits-all response for industry because the impact of GLP-1 drugs on taste seems to vary among users. It’s an area of research that will progress quickly as GLP-1 use increases and should be closely monitored so that brands can adapt accordingly. For now, balance seems to be the key.
