The science

The science behindWinter Light.

Every ingredient, every dose, and the research behind it. No proprietary blend, no hidden amounts, no miracle claims.

The science behind

How we choose what goes in

1

Studied ingredients

Each ingredient is in Winter Light because it has been studied in humans, not because it's trending.

2

Every dose on the pack

No proprietary blend. You always know exactly how much of each ingredient you take.

3

Honest about the evidence

We show how strong the research is for each ingredient, and we never claim more than it says.

Strong Several human trials or a meta-analysis Moderate Promising trials, more research needed Emerging Early but encouraging evidence
Natural caffeine + L-theanine

80 mg + 200 mg

Natural caffeine + L-theanine

Strong evidence

Natural caffeine from green tea, paired with L-theanine, an amino acid found in tea leaves. Together, they are one of the most studied pairings for alertness and focus.

In placebo-controlled trials, the combination improved the speed and accuracy of attention and made participants less susceptible to distraction. A 2014 meta-analysis confirmed effects on alertness and attention in the first two hours after intake.*

Research
Rhodiola rosea

400 mg

Rhodiola rosea

Moderate evidence

Known as "arctic root", rhodiola grows in cold northern climates and has a long history of traditional use in Scandinavia and Russia.

It has been studied in people under demanding conditions: physicians on night duty, students during exams and military cadets. Several of these trials reported lower mental fatigue than placebo.* A 2012 systematic review found the results promising, but noted that larger, high-quality studies are still needed.

Research
  • Darbinyan et al., Phytomedicine, 2000 (physicians on night duty) · Read the study
  • Spasov et al., Phytomedicine, 2000 (students during exams) · Read the study
  • Shevtsov et al., Phytomedicine, 2003 (military cadets) · Read the study
  • Ishaque et al., BMC Complementary and Alternative Medicine, 2012 (systematic review) · Read the study
Saffron extract

28 mg

Saffron extract

Emerging evidence

Saffron comes from the stigmas of the Crocus sativus flower, one of the most precious botanicals in the world.

In a 4-week, double-blind, placebo-controlled trial with 128 healthy adults, 28 mg per day of a standardized saffron extract was studied for its support of a positive mood.* The same trial found no effect at 22 mg, which is why Winter Light uses 28 mg.

Research
  • Kell et al., Complementary Therapies in Medicine, 2017 · Read the study
Vitamin D3

2,000 IU

Vitamin D3

Essential nutrient

Your skin makes vitamin D from sunlight, but not all year. A classic study showed that in Boston, winter sunlight from November to February is too weak for the skin to produce vitamin D3.

Vitamin D supports normal immune function and healthy bones.* At 2,000 IU, Winter Light stays well below the 4,000 IU daily upper limit set for adults.

Research
Vitamins B6 + B12

Vitamins B6 + B12

Essential nutrients

B vitamins are the quiet workers behind your energy. B6 and B12 both play a central role in normal energy metabolism, the process that turns food into usable energy.*

Research
Vitamin C

Vitamin C

Essential nutrient

An antioxidant your body cannot make on its own. Vitamin C supports normal immune function.*

Research

What we don't claim

The studies on this page tested individual ingredients, not Winter Light itself, and sometimes at different doses. We share them so you can see why each ingredient is in the formula.

Winter Light is a dietary supplement, not a medicine. It is not intended to diagnose, treat, cure, or prevent any disease. If you are pregnant, nursing, sensitive to caffeine, taking medication or have a medical condition, talk to your doctor before use.

One stick. Every dose on the pack.

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*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.