You Can Drink Your Ketones. Should You?

THE BOTTOM LINE:

Should ketones earn a spot in your supplement drawer?

If your goal is to improve your insulin sensitivity, ketone supplementation belongs in the reinforcements division — not the frontline defence.

They are not the first or the most powerful move.

And they are never a substitute for stable sleep, stress regulation, and recovery.

If your foundational defences falter, ketone supplements won’t win the war.
At best, they buy you time while you reinforce the foundations.

IF YOU’RE GOING TO USE KETONES, HERE’S WHEN

If you are reading my blogs, I just assume that you are highly intelligent and at least slightly nerdy about physiology 🤓.

You probably already understand the physiology behind ketones.

But, since assumption is the mother of all …, I present to you:

Ketones 101

Ketones are made in the liver from fatty acids.

Your body begins producing ketones when insulin falls and stored carbohydrates (glycogen) declines, allowing fat to be released and converted into ketones by the liver.

Normally, your body makes very small amounts of ketones when you are fed.
It makes a little more after an overnight fast.
It makes substantially more when insulin is low for longer periods.

Ketones are first and foremost:

• An alternative fuel source — particularly for the brain, but also the heart and muscles.
• Supportive of metabolic regulation.
• Can reduce inflammation.

But before we start pinning medals on ketones, we need to remember that they only show up when the frontline has done its job and the battlefield conditions are in order.

The Frontline

Frontline strategies that directly lower insulin and create the conditions for ketone production.

1. Time-Restricted Eating & Fasting

When you stop eating, insulin falls, fatty acids rise and the liver produces ketones.

The longer insulin stays low, the more pronounced the effect:

• An overnight fast: modest rise (~0.2–0.5 mmol/L)
• 16 to 24 hour fasts: substantially higher levels

2. Carbohydrate Restriction

Carbs stimulate insulin secretion.

Proteins do too — but carbs generally produce the largest rise in blood glucose and therefore insulin.

Several dietary approaches reduce carbohydrate intake, including ketogenic and Atkins-style diets.

These often recommend you should only get anywhere from 5% to 30% of your daily kilocalories from carbs.

Yikes! 🫣

I am more partial to these practical recommendations:

• Avoiding carb-heavy, late-night meals. We are naturally less insulin-sensitive at night.
• Being cautious of high carb breakfasts. Morning cortisol, glucose and insulin are already elevated (the “dawn effect”). No need to bump them up any further with bowls of cereal or toast and jam.

3. Exercise

Exercise lowers the demand for insulin because working muscles use glucose directly. In fact, contracting muscles can take up glucose independently of insulin.

As the body adapts to exercise, insulin sensitivity improves because of:

• Increased mitochondrial density.
• Increased muscle mass.
• Improved insulin receptor signalling.
• Reduced visceral adipose tissue (VAT).
• Greater muscle glycogen storage capacity.

Most forms of exercise lower insulin, albeit via different mechanisms:

• Low-intensity cardio? Helpful.
• HIIT? Also helpful.
• Resistance training? Especially powerful, because more lean muscle means a larger glucose “sink.”

Choose the form you can recover from and sustain.

I said “most forms of exercise”: if you’re pushing your exercise, but not recovering properly, your cortisol rises — increasing glucose production, which means insulin has to rise to manage it.

And although a contentious issue in the menopause arena, training — particularly when fasted or carbohydrate-restricted — improves your ability to shift into ketosis efficiently. In fact, most scientists reiterate that there is currently no scientific data to verify the claim that training in a fasted state is harmful to women, including midlife women.

It remains a personal choice — context matters.

Battlefield Conditions

Even the strongest frontline strategy will struggle if the battlefield itself is chaotic.

Chronic stress raises cortisol and adrenaline, both increase blood glucose production and reduce insulin sensitivity. If this becomes persistent, insulin levels rise to compensate.

Poor sleep independently lowers insulin sensitivity and increases next-day insulin levels.

So, it stands to reason that managing stress and protecting sleep reduces overall insulin demand.

When Supplementation Makes Sense

Now, if one or all of your frontline defences are compromised and your battlefield is foggy from poor sleep and elevated cortisol, but you still want some of the metabolic benefits of circulating ketones, then yes, supplementation is an option.

But you do really need to know that whilst supplements may elevate ketones — they do not lower insulin.

They are the reinforcements — not the strategy.

You might choose supplementation if you wish to:

• Support your cognitive function and/or your metabolism.
• Need help regulating your appetite.
• Need to reduce inflammation.
• Navigate disrupted sleep or high-stress lifestyles (e.g., shift workers, nurses, pilots).

There is this concept: “ketones beget ketones”, that raising circulating ketones may signal the liver to produce more, so you may not have to supplement continuously.

Types of Supplements

1. Ketone Salts
The most widely available form and contribute to a moderate rise in blood ketones.

2. Ketone Esters
More concentrated compounds that significantly elevate blood ketone levels. Potent — and famously unpleasant in taste!

3. Bioidentical Beta-Hydroxybutyrate (BHB Acid)
Structurally identical to the ketone the body naturally produces, these are more rapidly absorbed and taste better.

You may also increase ketone production indirectly with medium-chain triglycerides (MCTs) and certain ketogenic amino acids such as leucine.

If you are chasing ketosis for the additional physiological benefits of circulating ketones, head to the Sciency bit below to see how you know if you “are there yet”!

THE SCIENCY-STUFF

Before we go further: the real goal is improving insulin sensitivity and metabolic flexibility — because a low-insulin environment underpins most of the benefits associated with ketones.

Now, we know what ketones are (Ketones 101), but I was fascinated to learn that:

• Ketones are not just an alternative fuel source. Even when glucose is available, they function as metabolic and signalling molecules.
• Although the liver produces ketones, it does not use them itself.

Ketones as energy

When fuelling with ketones, people often describe it as “stable energy” — likely because blood sugar swings are smaller, and your body is relying more on fat than on frequent carbohydrate top-ups.

Ketones and the brain

Ketones are an alternative form of fuel specifically for the brain.

But more than that: they are actually the brain’s preferred fuel.

This is one reason ketogenic therapies have long been used in epilepsy, and why ketones are being studied in neurological conditions linked to impaired glucose metabolism (migraines, Alzheimer’s disease and others).

Ketones may still be used by the brain even if someone is insulin resistant.

Ketones and inflammation

If high INsulin predisposes one to INsulation and INflammation (those capital letters aren’t accidental), then it’s rather fitting that ketones are naturally anti-inflammatory molecules.

Ketones as signalling molecules

One ketone in particular, Beta-hydroxybutyrate (BHB), influences gene expression and cellular stress responses.

This may promote cellular repair, improve oxidative stress defences, and support protein regulation under metabolically stressed conditions.

All that in English means:

BHB isn’t just fuel. It’s more like a text message to your cells saying,
“Tidy up. Repair what’s damaged. Stay calm under pressure.” 💙

This signalling role may be one of the most important — and least appreciated — aspects of ketone biology.

Ketones and muscles

Since ketones support mitochondrial function and increased fatty acid oxidation, they may help preserve muscle and encourage using fat as fuel.

They support muscles — they don’t magically sculpt them! 💙

Ketones and fat

Ketones may even change how fat tissue behaves.

Fat — particularly VAT — isn’t just a storage depot; it sends hormonal signals. When it becomes more metabolically active, it may act less like a stagnant warehouse and more like responsive tissue, potentially supporting better metabolic signalling and improved insulin sensitivity.

Do be warned though:
even if your VAT becomes more metabolically active,
it doesn’t automatically get smaller or less.

If you’re consistently snacking and your insulin stays elevated, you may simply end up recycling the fat rather than reducing it. 🤦🏻‍♀️

These are the numerous really good reasons why we would want more ketones floating around inside us.

How Would You Know If You Have Ketones in Circulation?

Under well-fed conditions, circulating ketones are usually below 0.1 mmol/L.

After an overnight fast, they may rise to 0.2–0.3 mmol/L.

After prolonged fasting or sustained carbohydrate restriction, ketones typically rise above 1 mmol/L.

Nutritional ketosis is typically defined as ≥0.5 mmol/L.

Some research suggests that cellular signalling effects may become more pronounced in the 1–2 mmol/L range.

The gold standard of measuring blood ketones is with the finger prick test.

You can also measure blood ketones with a continuous ketone monitor, in the breath (less accurate) or in the urine (less reliable).

If you don’t have fancy gadgets or you are squeamish about little pricky things 😉, some indirect markers may suggest ketosis:

• Fruity smell on your breath.
• Reduced hunger.
• Increased urination.
• Temporary fatigue or headache during the early shift toward greater fat and ketone use.
• Increased mental clarity once adapted.

Here’s the thing:

Can You Have Too Much?

Research on sustained (~28 days) ketone supplementation in healthy adults has reported no negative changes in kidney function, blood glucose, triglycerides, cholesterol, electrolytes, body weight, or body composition — which is also why it’s not a fat-loss supplement.

The Critical Distinction

Ketones aren’t just backup fuel.

They are metabolic messengers that appear when the hormonal terrain shifts away from storage and toward fuel use. In that environment they influence mitochondria, inflammation pathways and broader energy regulation processes.

Which is why they can be really beneficial.

But:

• They do not replace the basics.
• They do not override chronic stress physiology.
• They do not force insulin down in a sustained way.

They are reinforcements. Not the general.

Raising ketones is not the same as becoming insulin sensitive.

You can drink ketones and remain metabolically inflexible.

You cannot improve insulin sensitivity without periodically lowering it.

That’s the physiology.

References (with supported statements)