Botanical Directory

Kratom strains — vein colors and alkaloid profiles.

Direct answer

Vein colors — red, white, and green — do not represent distinct plants. They describe post-harvest drying time, which changes the alkaloid ratio between mitragynine and 7-hydroxymitragynine. Yellow vein is a fermented or blended product, not a natural leaf color.

Medically reviewed by Dr. Irvine Russell · Updated April 2026

Understanding vein taxonomy

Red vein

Dried longer, often outdoors. Higher conversion to 7-OH metabolite — more sedating, analgesic.

White vein

Fastest-dried, typically indoors without UV. Preserves higher mitragynine — more stimulating, focus-oriented.

Green vein

Middle-ground processing — indoor start, outdoor finish. Balanced alkaloid spectrum; moderate energy and relaxation.

Yellow vein

Post-harvest fermentation or blend of red and green leaves. Not a natural leaf color; effects vary by producer.

Frequently asked

What is kratom?

Kratom (Mitragyna speciosa) is a tropical evergreen in the coffee family native to Southeast Asia. Its leaves contain alkaloids — primarily mitragynine and 7-hydroxymitragynine — that interact with opioid receptors.

Which strain is strongest?

Maeng Da is typically the most potent commercial strain, with mitragynine concentrations often above other strains. Potency also depends on producer, batch, and vein color.

Does vein color matter?

Vein color reflects post-harvest drying and processing, not distinct plant species. Red veins are dried longer (more sedating), whites are fastest-dried (more stimulating), greens fall in between, and yellow is a fermented or blended product.

How should beginners start?

Start with a mild or moderate-potency strain (Bali, Yellow Vein, Green Malay) at the lowest effective amount. Avoid mixing with opioids, alcohol, or benzodiazepines. Buy from AKA-GMP certified vendors only.