How to Make THC Lean — 4 Ingredient Cannabis Syrup Recipe

Want to know how to make THC lean at home? Cannabis syrup — also called THC lean, canna syrup, or CannaSyrup — is a concentrate-infused simple syrup that you can use in drinks, add to food, or consume by itself. This guide covers the 4-ingredient recipe using rosin (or any concentrate) and vegetable glycerin as an emulsifier.

Note: If your cannabis syrup separates after making it, check out this fix video — adding ½ tsp liquid lecithin solves the separation issue.

What Is THC Lean (Cannabis Syrup)?

THC lean is a concentrate-infused simple syrup. The name comes from the fact that it resembles the purple codeine syrup used in some hip-hop culture, but this version uses cannabis concentrate instead. Learning how to make THC lean at home gives you full control over potency, flavor, and ingredients. You can use rosin, FECO, distillate, wax, or shatter — whatever concentrate you have on hand.

4 Ingredients for the THC Lean Recipe

• 1 cup white sugar
• 1 cup water
• Decarbed cannabis concentrate (rosin, wax, distillate, shatter, etc.)
• 1 tablespoon vegetable glycerin (as emulsifier)

The vegetable glycerin cannabis emulsifier is the key ingredient. THC doesn’t bind to water — but it does bind to vegetable glycerin. Once the rosin is fully mixed into the glycerin, it can then be incorporated into your sugar water to create a stable cannabis simple syrup.

How to Make THC Lean — Step by Step

Step 1 — Decarb Your Concentrate

Before learning how to make THC lean, you need to activate your concentrate. Decarb rosin at 240°F (115°C) for 30 minutes. Other concentrates may have slightly different decarb times — check the specific concentrate you’re using. Decarbed concentrate is essential; without this step the THC won’t be active.

Step 2 — Mix Rosin With Vegetable Glycerin

Add 1 tablespoon of vegetable glycerin directly to your decarbed rosin. Use a silicone stirrer and mix until the vegetable glycerin cannabis emulsifier and rosin become one smooth, homogeneous mixture — no oil blobs floating around. A coffee cup warmer helps keep the mixture liquid while you stir. For a true double-boiler, place your glass container in a pot of warm water to gently heat while mixing.

Step 3 — Make the Cannabis Syrup With Rosin Base

In a separate pot, combine 1 cup sugar and 1 cup water over medium heat. Stir continuously until all the sugar dissolves. This cannabis syrup with rosin base needs the sugar fully dissolved before you add the concentrate mixture — don’t rush this step. Keep the heat low enough that the mixture doesn’t boil violently.

Step 4 — Combine and Finish the THC Lean Recipe

Once the sugar water is ready and your rosin-glycerin mix is homogenous, pour the concentrate mixture into the simple syrup while stirring. Continue stirring on low heat for a couple of minutes until the THC lean recipe looks like a single, uniform color. Remove from heat before it starts boiling. Warning: hot sugar syrup causes severe burns — use heat-resistant gloves and keep children away from the stove.

Step 5 — Bottle and Store

Pour the finished cannabis simple syrup into a clean glass bottle using a funnel. Let it cool completely to room temperature before refrigerating — putting hot syrup in the fridge can crack the glass. Shake the bottle every few minutes while it cools. Shake before every use. Store in the fridge for up to 4 weeks.

Cannabis Simple Syrup Dosing

To calculate cannabis simple syrup dosing, use a calculator like scientificedibles.com. For example: 2 grams of rosin at around 70% THC yields approximately 1,400–1,800mg total THC in the batch. If the batch makes 300ml of syrup, that’s roughly 4.5–6mg per millilitre. Start with 1–2ml to test your tolerance before consuming more.

How to Use THC Lean

Once you know how to make THC lean, the uses are endless. Add it to drinks to sweeten and infuse at the same time, drizzle it over desserts, mix it into lemonade or iced tea, or take it straight by the teaspoon. Because cannabis simple syrup dosing can vary based on your concentrate strength, always start low and wait 1–2 hours before taking more.