What Is THCa?

How is THCa different from THC?

Cannabis plants don't make much THC directly. They make THCa, an acid form of THC, in their resin glands. THCa has a slightly different structure, and on its own it doesn't produce the intoxicating effect people associate with cannabis. When it's heated, it loses part of its structure and becomes THC. This process is called decarboxylation.

Wikipedia's article on THCa (opens in a new tab) explains the chemistry in more depth.

When does THCa turn into THC?

Whenever it's heated enough. Lighting a pre-roll or flower converts THCa to THC as it burns. A vape coil does the same as it heats the oil. That's why smoking and vaping work with raw plant material and concentrates rich in THCa: the heat does the conversion at the moment you use it.

It's also why eating raw cannabis doesn't have the same effect as smoking it, and why edibles are made with cannabis that has already been heated.

Why do labels show THCa and total THC?

Because flower and many concentrates contain mostly THCa, a label showing only 'THC' would understate how much THC you'll get once it's heated. Many labels and lab reports therefore show THCa, THC and a 'total THC' figure that combines them, adjusted for the conversion. When comparing products, total THC is usually the most useful number; see how to read a cannabis label.

What are THCa diamonds?

Under the right conditions, THCa can be separated from an extract and grow into clear, glassy crystals. People call them diamonds. They're very concentrated, and they're used to add intensity to other products.

• Liquid Diamonds oil blends diamonds back into a terpene-rich oil, used in Jeeter Juice carts and All-in-One Diamonds vapes.
• Quad-Infused pre-rolls layer diamonds with rosin and kief.

Our posts on live resin vs Liquid Diamonds and what Quad-Infused means go into more detail.

Is THCa flower different from regular flower?

You may see 'THCa flower' advertised, especially online. All cannabis flower contains mostly THCa, so once it's heated it behaves like any other cannabis and produces THC. The difference is usually about how it's labelled and sold, not what it does when smoked. Legal treatment varies and has been changing, so it's important to buy from licensed sources in states where adult-use cannabis is legal.

Does THCa break down over time?

Slowly, yes. Heat, light and air gradually convert some THCa to THC, and some THC degrades further over long periods. That's one reason storage matters: products kept cool, dark and sealed stay closest to the lab results printed on the label. The effect over a few weeks or months is small if storage is good, but a product left in a hot car or a sunny window changes faster.

For pre-rolls, see how to store pre-rolls; for vapes, keep carts upright at room temperature, as explained in how to use a 510 cartridge.

How does THCa relate to the strain type?

Not directly. Indicas, sativas and hybrids all contain THCa as their main cannabinoid in raw form. The strain type and mood tags describe the overall experience a strain is known for, while THCa and THC describe how much of the main active compound it contains. Use both together; see indica vs sativa vs hybrid.

What should you keep in mind?

Products high in THCa will produce THC when you smoke or vape them, so treat them like any strong cannabis product. Start with a small amount, wait several minutes between puffs, avoid mixing with alcohol and never drive after using cannabis. Our start low, go slow post covers the basics, and what THC percentage means helps you read the numbers.

This post is general information for adults 21 and over and isn't medical advice.