AK 1995
- THC
- 18–25%
- Flowering
- 8–10 wk
- Terpene
- Myrcene
- Effect
- Energetic
- Difficulty
- Intermediate
Viper strain
Bred by Reeferman Seeds · Mexican
Strain facts
Checked Oct 21, 2026 · 4 sources
Viper is a very tall sativa that's challenging to grow. It was bred by Reeferman Seeds from Mexican. Its THC is about 21% (sources say 20–21%), higher than 46% of the 2,337 strains in our database that list THC. It flowers in about 10.5 weeks (one source lists 10–11 weeks).
Learn to grow Viper: Indoor & Outdoor Growing course, $199
- Type
- Sativa
- THC
- About 21%20–21% across 2 sources
- Top terpenes
- Myrcene earthy, musky
- Caryophyllene peppery, spicy
- Pinene pine
- Lineage
- Mexican
- Breeder
- Reeferman Seeds
- Grow difficulty
- Advanced1 source
- Flowering
- About 10.5 weeks10–11 weeks · 1 source
Free Viper grow sheet (PDF)
The grow facts from this page on one printable page, with a blank grow log for your plant.
4 sources for this profile
- Leafly public strain listing
- Weedmaps public strain listing
- Breeder information: Reeferman Seeds
Grow facts
Grow facts come from the breeder first, then seed banks and strain databases. With 2 sources we show the range and the middle; with 3 or more, the range and the median, after leaving out values far from the rest. The breeder's own value is the anchor, unless it is far from every other source (outside their range and more than 20% from their median); then we show the full range and the median of all of them. A fact from a single source is marked "1 source", and a fact no source lists is left out. Yields are converted to one unit: indoor per square meter, outdoor per plant.
CTU writes every profile from these facts; we do not copy other sites' descriptions. Values that are a generic default in the source data are left out. Last checked Oct 21, 2026.
Source: CTU strain dataset (public strain listings and breeder info, checked by CTU), verified Oct 2026. Potency, flavor and effects vary by grower, batch and plant. Facts no source lists are left out.
How to grow Viper
The grow facts a breeder or public strain listing gives for Viper.
- Flowering time
- About 10.5 weeks10–11 weeks · 1 source. Slower than 95% of strains with a listed time
- Plant height
- Very tallOne of 96 strains listed as very tall
- Difficulty
- Advanced1 source. One of 85 advanced-rated strains
Flowering window (weeks after the switch to 12/12)
- 1
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Sources: the breeder, seed banks and strain databases listed under sources, checked Oct 2026. Percentages compare with every strain in our database that lists the same fact.
About Viper
In public strain data, Viper is classed as a sativa attributed to Reeferman Seeds. Its listed lineage is Mexican.
Viper THC level
Public listings give Viper a THC level of 21%, which is around the middle of the range. Compared with all strains in our research dataset that have their own THC figure, it is higher than roughly 51% of them. Potency varies by grower, batch and lab, so read these numbers as typical values, not guarantees.
Viper aroma, flavor and terpenes
Flavor notes reported for Viper: mint, citrus, cheese and berry. Its top listed terpenes are myrcene (earthy, musky), caryophyllene (peppery, spicy) and pinene (pine). Myrcene is the lead terpene for about 44% of the high-confidence strains in our dataset, so it is a common profile. Terpenes shape smell and taste; their levels change from batch to batch.
Reported effects of Viper
People who have tried Viper most often report feeling energetic, talkative, focused, creative and tingly. These are user reports, not promises. Effects differ from person to person and depend on dose, setting and tolerance.
Growing Viper: what the data says
Its listed indoor flowering time is 10–11 weeks. That is longer than the 8–9 weeks listed for most strains. Grow difficulty is listed as advanced. Plants are listed as very tall. Listed resistance: pests high. Grow where home cultivation is legal, and follow your state rules.
Viper family tree
Parents and the strains bred from it, from published lineage.
Similar strains
Matched on shared parents, top terpenes, type and THC. Never on medical use.
Arcata Trainwreck
- THC
- 17–24%
- Flowering
- 8–10 wk
- Terpene
- Myrcene
- Effect
- Energetic
Cantaloupe Haze
- THC
- 14%
- Flowering
- 8 wk
- Terpene
- Myrcene
- Effect
- Uplifted
Crystal Meth
aka Crystal
- THC
- 18–24% · CBD 0.8–1.1%
- Flowering
- 8–18 wk
- Effect
- Energetic
- Difficulty
- Intermediate
Sativa strainsMyrcene strainsMint strainsStrains bred from Mexican
Where to buy
Find licensed dispensaries in your state
Only state-licensed stores, checked against official license lists.
Grow it
Flowering time, height and difficulty from the sources, then the full method in the Growing course.
