One of the biggest questions around ketogenic therapy is what happens when ketone levels fall. Is the effect immediate? Or do the benefits persist?
In this clip, metabolic psychiatry researcher and clinician Erin Louise Bellamy, PhD, explains why the answer isn’t straightforward.
“Once you’re producing ketones, those ketones are present and they are doing what they need to do.”
Even at lower levels, ketones are still present in the system.
“Even if you had like 0.3, 0.4 ketones, you still have ketones. You don’t have a ton, right? You could do more with more, but you still have some, and they’re doing something.”
But when ketone levels drop below what is often considered a therapeutic range, the response is not uniform. Bellamy describes a wide range of real-world responses seen in clinical practice.
For some individuals, changes can be rapid and pronounced.
“I’ve had people where they’ll drop below, say their range is 1.5 to two… within half an hour of them eating something and the ketones dropping, they’re hallucinating.”
For others, the shift is much slower. Symptoms may take days to reappear, or may emerge more subtly over time.
“It might be maybe two or three days, and then they start getting their low mood, low motivation, a little more anxiety, more irritable.”
And in some cases, there may be little to no immediate change at all.
“This is the part we don’t know yet. Not everybody responds the same way.”
Clip Highlights
What happens when ketones are still present but reduced
Why ketone levels don’t map neatly onto symptom changes
The range of responses when dropping below a therapeutic level
Clinical observations, from rapid shifts to delayed changes
Why individual variability is central to ketogenic therapy
Takeaway
There is no single, predictable response to falling ketone levels. In mental health applications, the relationship between ketones and symptoms appears highly individual.
🔜 Coming Soon: The Future of Metabolic Psychiatry: What’s Coming Next
Article behind the interview: Why Experts Are Exploring Ketogenic Therapy for Mental Health
