Superthrive Nutrients

Superthrive is one of the most iconic plant supplements in the history of horticulture — a concentrated vitamin and hormone solution that has been used by professional growers, nurseries and horticulturists worldwide for decades. The original formula, developed in the United States in the 1940s, combines vitamin B1 (thiamine) with Naphthyl Acetic Acid (NAA) — a synthetic auxin plant hormone — to produce a highly concentrated growth and rooting stimulant unlike anything else on the market.
Vitamin B1 and NAA — A Proven Combination
Superthrive’s effectiveness lies in the synergy between its two active ingredients. Vitamin B1 (thiamine) is a coenzyme involved in carbohydrate metabolism and energy production in root cells — essential for rapid root initiation and stress recovery. Naphthyl Acetic Acid (NAA) is a synthetic auxin that directly stimulates root initiation by triggering the hormonal pathway responsible for root cell differentiation. Together, these two compounds produce a measurably faster rooting response than either ingredient alone.
The concentration of Superthrive is extraordinary — just a few drops per litre is the standard dosage. A single small bottle treats hundreds of litres of nutrient solution, making it exceptionally cost-effective despite the premium appearance. Overdosing Superthrive can cause NAA toxicity symptoms (leaf curling) — always start at the recommended dose and adjust only if needed.
When to Use Superthrive
Use Superthrive at transplanting, during cloning, after stress events and as a general growth stimulator throughout the vegetative phase. It is compatible with all base nutrient ranges and growing media. We have been supplying Superthrive to UK growers since 2017. Browse the full range below.