You don’t buy energy. You make it. Here’s how, and why October makes it harder.

Every October, the shelf changes colour. Out go the lemons and the green boxes, in come the oranges and yellows, and one word starts turning up on everything: energy.

Energy drinks. Energy shots. Energy tablets. Energy blends, energy complexes, sustained energy, clean energy, energy without the crash.

It's a lovely word, and it's doing something quietly strange, because energy isn't an ingredient. It isn't sitting in a tablet waiting to be handed over. You are the only thing in the room capable of making energy, and you're doing it right now, continuously, out of your breakfast.

So what is in the tablet? Something genuinely useful, as it happens. Just something more interesting than one word on a box.

"Energy" gets used as if it means "feeling lively". Biologically it means something far more precise.

The currency your cells actually spend is a molecule called ATP. Every single thing your body does, from contracting a muscle to firing a neuron to thinking about what's for dinner, is paid for in ATP. And here's the part that reframes the whole category: you don't store it. There's no tank to fill. You hold a few seconds' worth at any moment and manufacture the rest on demand, all day, in tiny structures inside your cells called mitochondria. Think of them as power stations: millions of them, running a production line that takes the carbohydrate and fat you've eaten, strips electrons off it in a controlled sequence, and uses the energy released to build ATP.

Food goes in one end, ATP comes out the other, and you spend it immediately. Which makes "topping up your energy" a slightly odd idea: you can't fill something that doesn't hold anything.

They're not the fuel. They're the machinery.

A production line that size doesn't run on raw materials alone. Every step needs specific enzymes, and many of those only work with a particular vitamin or mineral slotted into them: a coenzyme, in the jargon. Riboflavin and niacin become part of the molecules that physically carry electrons down the line. Iron sits at the heart of the proteins that hand them along. Magnesium is required for ATP to be usable at all.

So the analogy isn't a fuel tank, it's a factory: fuel is what you ate, and the nutrients are the tools on the bench. Which explains how these products actually behave. If a tool is missing, the line slows down. Put it back and the line runs properly again. Add a second set of tools to a line that already has everything, and nothing happens. You've just got more tools.

Same as September: there's a register of approved health claims, the wording is fixed, and reading it closely is genuinely interesting. It's the clearest summary anywhere of what the evidence actually supports.

These nutrients carry the claim contributes to normal energy-yielding metabolism:

Riboflavin (B2) · Niacin (B3) · Pantothenic acid (B5) · Vitamin B6 · Vitamin B12 · Thiamine (B1) · Biotin · Vitamin C · Iron · Magnesium · Copper · Iodine · Calcium · Phosphorus · Manganese

And a slightly shorter list carries contributes to the reduction of tiredness and fatigue:

Riboflavin · Niacin · Pantothenic acid · Vitamin B6 · Vitamin B12 · Folate · Vitamin C · Iron · Magnesium

Now read the first one again, because the load-bearing word is normal.

Normal energy-yielding metabolism. Not enhanced. Not elevated. Not sustained-without-a-crash. The claim is that the nutrient is required for the process to run the way it's supposed to, which is exactly the same construction as September's immune claims, and it means exactly the same thing. These are maintenance claims. They describe what happens when you have enough, not what happens when you have extra.

What the register doesn't contain, for any nutrient, is a claim that it creates energy, adds energy, or stops the afternoon dip. The assessed evidence supports maintenance, meaning the nutrient is required for the process to run properly, and it stops there.

Which makes the shorthand fairly understandable, honestly. "Energy" fits on a box. "Contributes to normal energy-yielding metabolism" does not, and it sounds like a pension statement. Every label in the category reaches for the short version, and there's nothing sinister in that. A pack has a few words to work with and has to be readable across a shop aisle.

The distinction worth making isn't about the word on the front. It's whether there's anything underneath it. B vitamins genuinely carry energy-metabolism and tiredness claims, so the shorthand is compressing something real. You can go and read the long version, and it says what the short version gestures at. That's a different thing from a word with nothing behind it at all, which is where September's "immune-boosting" sat: no authorised version of that claim exists to compress, because the evidence never supported one.

We just happen to think the long version is the more interesting one, and it has the considerable advantage of being what the research actually found.

Because the light changed, and quite a lot of your biology is keyed to it.

Morning light is the main signal your body clock uses to decide when you should be alert. As the mornings darken, that signal arrives later and weaker, and the timing drifts. You're not getting less capable. You're getting a less clear instruction about when to be awake. Then the rest stacks up: dark when you leave, dark when you get back, so you move less, you're indoors more, and food gets more repetitive. None of that is a personal failing. It's October happening to a mammal.

And here's the part worth saying: tiredness has an enormous number of causes, and most of them aren't a nutrient shortfall. Sleep, stress, illness, thyroid function, mood, medication and simply having a demanding week all produce the same feeling. If you're persistently, unusually exhausted, the kind that doesn't lift after a good weekend, that's a conversation with your GP and probably a blood test rather than a decision to make in an aisle. A more useful answer than a tablet, so it's the one we'd rather give you.

There's a narrow, real case: if you're actually short of one of those nutrients, correcting the shortfall matters. The line was slow because a tool was missing.

The two worth knowing about are iron and B12, for everybody. Iron deficiency is the commonest nutritional deficiency on the planet across every kind of diet, and B12 turns out to be an absorption story rather than a menu one. They've earned their own place this month. The third is vitamin D, which stops arriving from sunlight around now in this half of the world, and is a separate story again.

And if you're not short, topping up doesn't do much. We sell supplements and we're happily telling you that, because a supplement you don't need isn't a good use of your money.

Worth a paragraph, since it's the most popular energy product on earth and it doesn't do what most people think.

Caffeine doesn't create energy, and it doesn't go anywhere near your mitochondria. What it does is block adenosine, a molecule that accumulates in your brain the longer you're awake, whose job is to tell you you're tired. Caffeine fits the same receptor and sits in the seat so adenosine can't. So the tiredness doesn't go away; the message does, temporarily, while the adenosine keeps building up behind the blockade. Which is why it all arrives at once later on.

That's not an argument against coffee. We're British; that would be a strange position for us to take. It's just a volume control on a signal rather than a source of anything.

Active Energy is the B-vitamin-led one: riboflavin, niacin, pantothenic acid, B6 and B12, with iron at 100% of NRV and vitamin C at 200%. Two notes on it, in the spirit of the rest of this piece. First, the B12 figure looks faintly ridiculous on paper, and there's a genuinely good reason for that which we went into in September: the amount of B12 you absorb from a single dose hits a ceiling of roughly a microgram whatever you swallow, so the number on the label and the amount that reaches you are two different quantities (the study, and its limitations, are here). Second, most energy formulas reach for caffeine. We built ours on B vitamins and two adaptogenic herbs instead: rhodiola and schisandra, 200mg of each, which makes them the two largest ingredients in the capsule. The evidence on botanicals hasn't been through formal assessment in the UK yet, so the vitamins are what carry the claims here, and with eight of them on the tiredness and fatigue list, they carry them well.

MultiVit covers the same ground more broadly, with iron and vitamin C in the same tablet, which matters more than it sounds, and is the next blog's subject, along with the two B12 formats (sublingual and 1000mcg sustained release).

And Magnesium Complex carries both the energy-metabolism and the tiredness claims. It's the one to look at if your actual problem is winding down rather than starting up.

None of these are thrilling. All of them are free, and they act on the mechanisms above rather than around them.

1. Get outside within an hour of waking, even when it's grim. This is the big one. Your body clock takes its cue from morning light, and an overcast British morning is still dramatically brighter than any room you own. We're talking orders of magnitude, not a bit. Ten minutes on the way to the car counts. The point isn't the walk, it's the light hitting your eyes early enough to set the clock for the day.

2. Keep your wake time steadier than your bedtime. Counter-intuitive, but the clock anchors to when you get up and see light, not when you turn in. A consistent alarm does more than a consistent bedtime, and it makes the bedtime easier anyway.

3. Move before the light goes, not after. Not for the exercise so much as the timing: activity in daylight reinforces the same signal the morning light started. A lunchtime lap of the block on a Tuesday in October is worth more than it looks.

4. Eat at roughly regular times. The ATP production line runs on what you've eaten. Long erratic gaps followed by a large late dinner is a recipe for feeling flat in the afternoon and wired at bedtime, and it's an easy pattern to drift into once the evenings close in.

5. Give caffeine a curfew. See the adenosine section. It's blocking a message, not removing it, and it hangs around for hours. If afternoon coffee is followed by a difficult bedtime followed by a tired morning that needs more coffee, that loop is worth breaking at the only point you control.

If you do one of these, do the first one. It costs ten minutes and it's the closest thing here to a free lunch.

You can't buy energy, but you're already remarkably good at making it, constantly, without being asked, out of whatever you had for lunch. The things that most affect how well that goes are light, sleep, movement and eating enough of the right stuff, none of which come in a bottle and all of which are free. Nutrients matter when you're short of them, and not much when you aren't.

It's a quieter story than one word on a box can tell. It's also the one where you're in charge of most of the variables, which we'd argue is the better deal.

You're not lazy. It got dark. Get some morning light, go to bed at roughly the same time, and eat like someone who's read the list.