The best scents for energy and happiness

Some days are just harder than others. Nothing has gone especially wrong, but everything takes a bit more effort than it should. You wake up tired, the to-do list feels heavier than usual, and by mid-afternoon you're running on empty.

In the darker months, those days come round more often. It's dark when you get up and dark again by half four, and it's hard not to let the grey outside seep in.

Low energy and low mood tend to arrive together, and you can't simply decide to feel brighter. Telling yourself to cheer up has never worked for anyone.

What you can do is change what's around you. Open the curtains, put a song on, step outside for five minutes. And one of the fastest ways to change how a room feels is the smell of it.

We'll be honest about what the research does and doesn't show further down. But first, why some scents feel like opening a window.

Why bright scents lift your mood

Smell skips the brain's sorting office. Scent signals go almost straight to the amygdala and hippocampus, the parts that handle emotion and memory. (We go into the wiring in our post on scent and memory.) That's why a smell can change your mood before you've consciously noticed it.

Citrus and mint oils seem to work on the "get up and go" side of things. A handful of studies have measured it:

• Lemon lifts mood. In a 2008 study at Ohio State University, 56 people smelled lemon, lavender or plain water. Lemon reliably put people in a better mood, even when they didn't know what they were smelling.
• Orange wakes you up. In a 2005 study, people who breathed in sweet orange oil felt more alert, and their heart rate went up slightly. That's the opposite of what happens with sleepy scents like lavender.
• Peppermint sharpens. In a 2008 Northumbria study of 144 people, peppermint left people feeling more alert and helped their memory too.

There's something simpler going on as well. Bright, fresh smells are linked in most of our heads with clean, sunny, good things: a squeezed orange at breakfast, a lemon cake, fresh mint in a summer drink. Smell one and your brain hands back a little of that feeling.

Telling yourself to cheer up has never worked for anyone.

Five scents for when you need a lift

1. 01

   Sweet orange: the happy one

   Juicy, warm and sunny, like peeling an orange in your hands. Sweet orange is the scent we'd pick if we could only keep one, because it lifts a flat mood almost instantly. It's energising without being sharp, which makes it easy to live with all day. Reach for it when: you need cheering up more than waking up.

2. 02

   Lemon: the one with the evidence

   Clean, sharp and zingy. Lemon has the best research behind it for mood, thanks to that Ohio State study. It also makes a room smell freshly cleaned, which is half the battle on a lazy Sunday. Reach for it when: you want the house, and you, to feel fresh.

3. 03

   Peppermint (and spearmint): the quick wake-up

   Cold, clean and impossible to ignore. Peppermint has the most research for alertness. Spearmint is its softer, sweeter cousin, gentler in a blend and easier to live with. Reach for it when: it's mid-afternoon and your energy has fallen off a cliff.

4. 04

   Bergamot: the one that lifts and calms

   The scent of Earl Grey, citrusy with a soft floral edge. Bergamot is unusual because it brightens your mood and has been linked to lower stress at the same time. Good for days when you're low and a bit frazzled. Reach for it when: you're flat and on edge at once.

5. 05

   Basil: the tired-brain one

   Green, peppery and a little sweet, like tearing leaves for a pasta sauce. Aromatherapists have long used basil for mental tiredness, though honestly the research is thin. It's on the list because it adds a fresh, herby edge that stops citrus feeling sugary. Reach for it when: your head feels foggy after a long day.

Our name, AIRO, means "to lift up", so this is the corner of aromatherapy closest to our hearts. Sweet orange and bergamot are in our SMILE blend, alongside bitter orange and neroli, which you'll find in SMILE: The Happiness Candle and the SMILE diffuser set. It's our founder Lisa's favourite blend and one of our best sellers. Lemon, sweet orange, spearmint and basil make up our EAT blend, in the EAT candle, made to freshen the kitchen after dinner and get the conversation going again. Every AIRO candle is made with pure essential oils and plant-based wax, in handblown glass you can refill, and every sale supports Dementia UK.

If you're new to this: start with sweet orange. It's the easiest scent to like, and it works as well at 8am as it does at 4pm.

How to actually use them

Bright scents work best in the parts of the day that need a push. A few ways to get the most from them:

• Start the morning with it. Light a candle or switch on a diffuser while the kettle boils. It's a small signal that the day has started, and on dark winter mornings it helps more than you'd expect.
• Use it for the 3pm slump. That's when energy dips for most of us. A few minutes of peppermint or orange near your desk can be the pick-me-up you'd otherwise get from a biscuit.
• Pair it with daylight. Open the curtains or step outside, then come back to a room that smells bright. Light and scent together make a stronger signal than either on its own.
• Keep it for daytime. Energising scents and bedtime don't mix. Save softer scents like lavender for the evening, so each one keeps its job.
• Freshen the kitchen. Citrus and mint are great after cooking, when the room smells of dinner and everyone's slumped. It changes the feel of the room fast.
• Go lighter than you think. Peppermint especially is punchy. If you can smell it from the next room, it's too much.

A few safety basics

• Citrus oils and sunlight don't mix. Lemon, bergamot and some orange oils can make skin burn more easily in the sun. Never put them neat on your skin.
• Keep peppermint away from little faces. Don't diffuse peppermint close to babies or young children, as it can affect small airways.
• Think about your pets. Cats in particular are sensitive to some oils, including citrus. Keep the room aired, and don't shut a pet in with a lit candle.
• Check first if you need to. If you're pregnant, breastfeeding, have asthma or epilepsy, or take regular medication, have a quick word with your GP or midwife.
• Never leave a lit candle alone. Keep it away from curtains, children and pets.

What the evidence says, honestly

The research on scent and mood is encouraging but limited. The studies are small, and most measure how people say they feel over a few minutes. The Ohio State study is a good example: lemon clearly lifted people's mood, but it didn't change their stress hormones, blood pressure or immune system. Scent seems to change how you feel, not what's happening in your body.

That's still worth having. A better mood on a grey afternoon is a real thing, even if it's a small one.

If low mood has stuck around for more than a couple of weeks, or it's getting in the way of daily life, please talk to your GP. If the dark months always hit you hard, it's worth asking about seasonal affective disorder too. Scent is a support, not a treatment.