Nutritional values	For 250mL (8g powder)	Per 100mL
Energy value	109 kJ / 26 kcal	44 kJ / 10 kcal
Fat	0.14 g	0.05 g
of which saturated fatty acids	0.04 g	0.02 g
Carbohydrates	3.62 g	1.45 g
including sugars	0.42 g	0.17 g
Dietary fiber	0.95 g	0.38 g
Proteins	2.07 g	0.83 g
Salt	0.04 g	0.01 g

Nutritional information per serving (8g)	Quantity (mg)	%VNR*
Magnesium	187.5 mg	50%
Zinc	5 mg	50%
Chromium	20 µg	50%
Selenium	27.5 µg	50%
Potassium	300 mg	15%
Vitamin B1	0.55 mg	50%
Vitamin B2	0.7 mg	50%
Vitamin B3	8 mg	50%
Vitamin B5	3 mg	50%
Vitamin B6	0.7 mg	50%
Vitamin B8	25 µg	50%
Vitamin B9	100 µg	50%
Vitamin B12	1.25 µg	50%
Vitamin D3	5 µg	100%
Vitamin K2	37.7 µg	50%
Acerola (extract)	353 mg	-
of which vitamin C	60 mg	75%
Spirulina	500 mg	-
including	0.6 mg	4.3%
Marigold (extract)	100 mg
excluding lutein	5 mg
Japanese Pagoda Tree (extract)	52.7 mg
of which quercetin	50 mg
Hyaluronic acid	55 mg
CoQ10	50 mg
Bifidobacterium bifidum	5 Bn CFU
Lactobacillus acidophilus	5 Bn CFU
Glycine	250 mg
L-glutamine	250 mg
Taurine	250 mg

The Morning Coffee Paradox ☕️

Jun 16, 2026

By Arthur Legrand

Hello,

It's a habit shared by millions of people. You wake up feeling a bit heavy because of the night's heat, and the first reflex is to rush to the coffee machine to switch on "productivity mode".

Yet from a purely physiological standpoint, this move creates a real paradox in summer. Let me explain why!

The Surprising Fact: -0.5 liters on the Meter Every Night 🥵

During summer, even if you sleep without moving, your body works hard to regulate its internal temperature. Through breathing and invisible sweating, you lose an average of 400ml to 500ml of water per night (that's huge!).

So in the morning, you wake up in a state of mild dehydration. Your blood volume is lower, your heart beats a little faster to compensate, and that's exactly what creates the sensation of mental fog when you wake up.

Why Coffee Makes It Worse ☕️

Caffeine is a fantastic stimulant, but it's also a diuretic (= it promotes the elimination of water and mineral salts through urine). If the first liquid you drink upon waking is an espresso:

You provide no usable fluid to your thirsty cells.
You push your body to eliminate what little water it has left.
You mask this lack of water with an artificial burst of excitement... which you'll pay for with a huge slump before lunchtime!

The Right Reflex: Prioritize Mineral Rehydration 💧

Before switching on the coffee machine, your metabolism needs to recover the water and electrolytes lost overnight.

That's where Onday makes all the sense in the world. By drinking your 44 nutrients in a large glass of cool water as soon as you get up, you provide, among other things, highly bioavailable potassium and magnesium. Potassium drives water straight into the heart of your cells to get things going again, while magnesium gently wakes up your nervous system.

Discover!

My tip: drink your Onday when you wake up, let 20 minutes pass so your tissues fully rehydrate... and then, enjoy your coffee. Your energy will stay stable and steady throughout the day!

Enjoy your summer mornings, and see you very soon for more tips!

Take care of your energy,

Arthur

The first all-in-one routine to be the favourite version of yourself, every day.

contact@onday.fr

1 Energy

Vitamins B1, B2, B3, B5, B6, B8, B12, C and magnesium contribute to normal energy-yielding metabolism. Ashwagandha and ginseng help to feel more energetic.

2 Immunity

Vitamins B6, B9, B12, D, C, selenium and zinc contribute to the normal functioning of the immune system.

3 Sleep

Vitamins B2, B3, B5, B6, B9, B12, C and magnesium contribute to reducing fatigue. Ashwagandha contributes to falling asleep.

4 Digestion

Ginger promotes digestion and normal functioning of the stomach, which contributes to digestive well-being. Milk thistle supports digestion.

5 Stress

Ashwagandha has adaptogenic properties that help the body cope with stress and promote emotional stability.

6 Blood sugar

Chromium, Zinc and Ginseng contribute to the maintenance of normal blood sugar levels.

7 Skin

Vitamins B2, B3, B8 and zinc contribute to the maintenance of normal skin. Vitamin C contributes to normal collagen formation for the normal function of bones, cartilage, gums, skin, teeth.

8 Focus

Vitamins B1, B3, B6, B8, B12, C and magnesium contribute to normal psychological functions. Ashwagandha and Ginseng contribute to optimal mental and cognitive activity.

Nutritional values

Ingredients

The Morning Coffee Paradox ☕️

The Surprising Fact: -0.5 liters on the Meter Every Night 🥵

Why Coffee Makes It Worse ☕️

The Right Reflex: Prioritize Mineral Rehydration 💧

Reading next

The first all-in-one routine to be the favourite version of yourself, every day.