Every essential oil bottle on Amazon says "100% pure". That phrase costs nothing to print, so it tells you nothing. What does tell you something is whether a brand lets you see the lab report for the exact batch in your hand.
That is how this list is ordered. We did not smell or test these oils ourselves. We checked each brand's own website for one thing: can a customer look up the GC/MS test for their batch without asking? The brands that say yes come first.
Gas chromatography with mass spectrometry splits an oil into its individual compounds and measures how much of each is there. A lavender report should show linalool and linalyl acetate as the main components. If a cheaper oil or a synthetic fragrance has been added, it usually shows up as compounds that do not belong or ratios that are off. A report does not make an oil good, but a brand that publishes reports is letting outsiders check its work.
| Brand | Batch test reports | Where to find them |
|---|---|---|
| Plant Therapy | Published for every batch | "Test Reports" on each product page, matched to the batch code on the bottle |
| Rocky Mountain Oils | Published for every essential oil | Free on their website |
| Edens Garden | Published | "Reports" on each product page |
| Aura Cacia | Published | A GC/MS documents page on their site |
| NOW | Certificate of analysis by lot | cofa.nowfoods.com, using the lot number on the bottle |
| Handcraft Blends | Not published | The brand says every batch is lab tested |
| Majestic Pure | Nothing found | No testing information on their site when we checked |
Checked on each brand's own website in September 2026. Policies change, so look again before you rely on it.

Each bottle carries a batch code, and the report for that code sits on the product page. Plant Therapy also runs a KidSafe line, blends it describes as formulated for children aged 2 to 10. That matters if you diffuse in a home with young kids, because many popular oils are not recommended around them.
Bottles are small, often 10 mL, so the per-bottle amount is modest.
Plant Therapy Lavender on Amazon →(paid link)
Rocky Mountain Oils states that it provides GC/MS results for every essential oil free of charge on its website, and it offers a 90-day return policy. On transparency it is as open as Plant Therapy.
Rocky Mountain Oils Lavender on Amazon →(paid link)
Edens Garden posts GC/MS reports under "Reports" on its product pages. It also sells several lavenders by origin, such as Bulgarian and French, which is useful if you care about the difference in scent.
Edens Garden Lavender on Amazon →(paid link)
Aura Cacia says every batch of its essential oils is GC tested, and it links to its GC/MS documents from its quality page. You will also find it in many natural food stores, so you can compare in person.
Aura Cacia Lavender on Amazon →(paid link)
NOW is a supplement company that also sells essential oils. Since early 2023 you can type the lot number from your bottle into cofa.nowfoods.com and see its certificate of analysis. It is a different document from a full GC/MS report, but it is tied to your batch.
NOW Lavender on Amazon →(paid link)
The brand this site started with. Its standard bottle is 4 oz, much larger than the 10 mL bottles most rivals sell, which suits people who diffuse every day. It says every batch is lab tested, but you cannot look the result up. If that matters to you, pick one of the brands above; if you mostly want a lot of oil for the diffuser, this is the practical choice.
Handcraft Blends Lavender on Amazon →(paid link)
Also sold in 4 oz bottles. We found no information about testing or reports on its website. That does not mean the oil is bad. It means you would be taking the label on trust.
Majestic Pure Lavender on Amazon →(paid link)We are not going to name brands to avoid, because naming one would need evidence we do not have for that brand. What we can do is list the signs that should make you put a bottle back.
Independent testing has found contaminants in some retail essential oils: Environmental Health News reported phthalates in oils from several popular brands. Published batch reports are the easiest way for an ordinary buyer to lower that risk.
For a diffuser, you use a lot of oil and nothing touches your skin, so bottle size matters more than it does for skincare. That is where 4 oz bottles from Handcraft Blends or Majestic Pure make sense. If you diffuse around children or pets, choose on safety first: see oils and cats, oils and dogs, and our diffuser how-to.
If you want to be able to check what you bought, start with Plant Therapy, Rocky Mountain Oils or Edens Garden. If you want the most oil for daily diffusing and accept the label on trust, Handcraft Blends is the one we know best.
By the standard we use, published batch test reports, Plant Therapy, Rocky Mountain Oils and Edens Garden lead. "Best" by scent is personal and we do not rank that.
Not necessarily. Price alone does not prove anything either way. A published test report for your batch is better evidence than price.
The brand says every batch is lab tested. It does not publish the reports, so a customer cannot check a specific bottle. See our Handcraft Blends review and comparison with Plant Therapy and Rocky Mountain Oils.
Brand policies checked September 2026.