Nootropics Index - Save on smarter supplements
Isolated phytochemicals & plant compounds

Forskolin

Forskolin / Coleus barbatus (Coleus forskohlii) diterpene

Forskolin is the active diterpene in Coleus forskohlii extracts. Small human trials of standardized extracts report mixed body-composition results and do not establish focus, memory, or productivity benefits. Compare listings by active forskolin per serving and extract standardization; keep blood-pressure, blood-thinner, and long-term-safety uncertainty in view.

Physical PerformanceLibido VitalityNitric Oxide RelatedBlood Flow SupportGlucose MetabolismStandardized ExtractIsolated Compound
Updated August 2026/6 min read/14 citations
Reviewed by the NootropicsIndex editorial team.Method: prioritize cited human research and official safety or regulatory sources; compare retailer-listed prices without endorsing products.Affiliate disclosure
Extra caution

Who should avoid this or get expert review first

This is not a recommendation to use. These groups should treat the profile as a reason to slow down and verify safety, rules, and personal context.

  • Avoid during pregnancy10Human pregnancy safety data are absent. A human placental-cell experiment raised concern, but it is not proof of clinical harm.
  • Avoid with polycystic kidney disease5MSKCC advises people with polycystic kidney disease not to use forskolin preparations.
01

What is it?

Active compound versus extract

1

Forskolin is a labdane diterpene found in Coleus forskohlii extracts. Retail listings commonly name the extract, so compare active forskolin per serving rather than extract weight alone.

Not a proven nootropic9
The cited supplement evidence consists of small oral body-composition studies and does not establish reliable focus, memory, or productivity effects.
Research boundary9
Active forskolin, a standardized Coleus extract, and a product’s labeled percentage are different comparison units. Small metabolic studies should not be read as cognitive-enhancement evidence.
02

Names, aliases and forms

Common NameForskolin
Chemical NamesColforsin; Labdane diterpene
Extract NameColeus forskohlii extract
Latin NamesColeus forskohlii; Plectranthus barbatus
Scientific NameColeus barbatus
Cas Number66575-29-9
Pubchem Cid47936
Molecular FormulaC22H34O7
Standardized Extract7.5% and 10%+ forskolin extracts
03

Mechanisms of action

Adenylyl cyclase and cAMP

1

Forskolin activates adenylyl cyclase, a cellular enzyme that raises cyclic AMP (cAMP). This mechanism does not prove a cognitive benefit, but it helps explain why medication-interaction context matters.

04

Potential effects and evidence map

Human research on standardized Coleus forskohlii extracts is limited, small, and inconclusive for weight loss or body composition. The primary oral trials followed participants for 12 weeks, and they do not establish cognitive, productivity, or long-term supplement benefits.

Effect domainMagnitudeGrade
Physical energy / endurance9
CumulativeConfidence: Medium

Small body-composition trials do not establish an endurance or physical-performance benefit.

Note The available oral trials measured body composition over 12 weeks, not exercise performance.

0/5
C
Libido / vitality2
CumulativeConfidence: Medium

One small male trial does not establish a testosterone or vitality benefit for general supplement users.

Note Do not generalize findings in men with overweight or obesity to hormone optimization or sexual-health outcomes.

0/5
C
Memory / learning9
UnknownConfidence: Medium

No reliable human evidence establishes memory, learning, focus, or productivity effects.

Note Forskolin’s cAMP pharmacology is not evidence of cognitive enhancement.

0/5
E
05

Typical dosages and timing

Active forskolin950 mg/day

Small body-composition trials commonly used 250 mg of 10% Coleus forskohlii extract twice daily. This is trial context, not a personal dosing recommendation.

10% extract950 mg in 500 mg

At 10% forskolin, 500 mg of extract supplies about 50 mg active forskolin. A lower-percentage product needs more extract to match that active amount; a higher-percentage product needs less.

06

Timing & effect horizon

Effect horizonCumulative
Cumulative
Study window9Cumulative
12 weeks
What the study window means9

The 12-week observation period describes the research window. It does not establish a same-day onset, an effect duration, or a recommended cycle.

No established onset or cycle9

Reliable healthy-user onset, subjective duration, The time for blood levels to fall by half during the final elimination phase.Source, tolerance, and cycling data for oral supplement use were not identified.

07

Safety, side effects and risk profile

Cardiovascular caution5
Confidence: Medium

Possible blood-pressure and heart-rate effects are targeted cautions, not established healthy-adult harms.

Note MSKCC lists low blood pressure and slow heart rate. Laboratory findings suggest potential additive effects with blood-pressure medicines, while clinical relevance has not been established.

2/5
C
Interaction risk5
Confidence: Medium

Blood-pressure medicines and blood thinners are the main interaction contexts to check.

Note MSKCC notes laboratory evidence for potential additive effects with beta-blockers, vasodilators, ACE inhibitors, calcium-channel blockers, warfarin, and other blood thinners; clinical relevance is uncertain.

2/5
C
Pregnancy / lactation caution10
Confidence: Low

Avoid during pregnancy; direct clinical safety evidence is absent.

Note A human placental-cell experiment raised concern but is not proof of clinical harm. This targeted precaution does not establish a healthy-adult base risk.

2/5
D
GI discomfort9
Confidence: Medium

Loose stools and more frequent bowel movements are reported tolerability issues.

Note The NIH fact sheet describes this signal in humans; short 500 mg/day, 10%-extract trials did not report more serious adverse events.

1/5
C
Evidence uncertainty9
Confidence: High

Marketing claims can exceed the limited, mixed human evidence.

Note NIH characterizes human research as very limited and inconclusive; no reliable cognitive evidence was identified.

2/5
B
Liver / kidney caution5
Confidence: Medium

Polycystic kidney disease is a specific caution; broader oral kidney harm is not established.

Note MSKCC specifically advises against forskolin preparations for people with polycystic kidney disease. This targeted caution does not establish a general healthy-adult kidney risk.

2/5
C
Blood pressure and heart-rate caution5

MSKCC lists low blood pressure and slow heart rate as potential effects. Laboratory findings suggest possible additive effects with blood-pressure medicines, although the clinical relevance has not been established.

Loose stools and GI symptoms5

MSKCC lists diarrhea and gastrointestinal symptoms as potential tolerability effects.

Animal-only liver signal for extract14

A 10% forskolin Coleus root extract caused liver toxicity in mice; corresponding pure forskolin did not reproduce the hepatic findings in that study. This animal finding does not establish human liver harm from oral forskolin or extract products.

Post-marketing GI signal for extract13

A post-marketing survey of Coleus extract products found mostly gastrointestinal reports and an association between claimed extract amount and diarrhea. Self-reported product-level data cannot establish individual causality or risk from pure forskolin.

Do not put oral products in the eye5

Forskolin has eye-pressure research, but oral extracts, powders, capsules, and topical products not designed for ophthalmic use should not be placed in the eye.

08

Interactions and cautions

Medication interactions to check5

MSKCC notes possible additive effects with beta-blockers, vasodilators, ACE inhibitors, calcium-channel blockers, warfarin, and other blood thinners. The cited interaction evidence is laboratory-based, so clinical relevance remains uncertain.

CYP3A is a preclinical signal12

Cultured-hepatocyte research suggests that forskolin can induce CYP3A. This is a preclinical signal, not evidence of a clinical drug interaction.

10

Practical buying and quality notes

  • Compare the label’s percentage standardization and active forskolin per serving, not bottle grams alone. Products that list only extract weight do not make active-dose comparisons straightforward.7
  • For powders and capsules, compare percentage forskolin, extract amount per serving, active forskolin per serving, batch assay, botanical identity, and whether the listed price is per gram of extract or per milligram of active forskolin.7
  • The small human trials are mixed and inconclusive. Use standardized active amount and label transparency as the first comparison filters rather than reading body-composition or testosterone marketing as settled evidence.9
11

FAQ

What is Forskolin?

1

Forskolin is a diterpene found in Coleus forskohlii extracts. It activates adenylyl cyclase and cAMP signaling, a mechanism that is not itself proof of a consumer benefit.

What is the Forskolin dosage?

9

The main trial context was 250 mg of 10% Coleus extract twice daily, which supplies about 50 mg/day active forskolin. Different extract percentages change the extract amount needed to reach a comparable active amount.

How long is Forskolin studied for?

9

The principal oral trials followed participants for 12 weeks. That duration is not evidence for a personal cycle length or a same-day effect.

Does Forskolin help focus or memory?

9

No reliable human evidence establishes focus or memory benefits. Small oral research has instead examined body composition and metabolic measures.

Who should be especially cautious with Forskolin?

5

MSKCC specifically flags polycystic kidney disease and potential interaction context with blood-pressure medicines and blood thinners. These situations need individualized clinical guidance.

12

References

  1. PubChem. Forskolin (CID 47936). Accessed 2026-07-01.
  2. Godard MP, Johnson BA, Richmond SR. Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men. Obes Res. 2005;13(8):1335-1343.
  3. Henderson S, Magu B, Rasmussen C, et al. Effects of Coleus forskohlii supplementation on body composition and hematological profiles in mildly overweight women. J Int Soc Sports Nutr. 2005;2:54-62.
  4. Loftus HL, et al. Coleus forskohlii extract supplementation in conjunction with a hypocaloric diet reduces the risk factors of metabolic syndrome. Nutrients. 2015;7(11):9508-9522.
  5. Memorial Sloan Kettering Cancer Center. Forskolin. Last updated 2023-06-02. Accessed 2026-07-01.
  6. U.S. Food and Drug Administration. Structure/Function Claims. Accessed 2026-08-20.
  7. BulkSupplements. Coleus Forskohlii Extract (7.5% Forskolin) Powder product listing. Accessed 2026-07-01.
  8. LiftMode. Coleus forskohlii Extract 10+% Forskolin product listings. Accessed 2026-07-01.
  9. National Institutes of Health Office of Dietary Supplements. Dietary Supplements for Weight Loss: Health Professional Fact Sheet. Accessed 2026-08-20.
  10. Rat P, et al. Forskolin induces endocrine disturbance in human JEG-3 placental cells. Toxics. 2022;10(7):355.
  11. Royal Botanic Gardens, Kew. Coleus barbatus (Andrews) Benth. ex G.Don. Plants of the World Online. Accessed 2026-08-20.
  12. Ding X, Staudinger JL. Induction of drug metabolism by forskolin: the role of the pregnane X receptor and protein kinase A signal transduction pathway. J Pharmacol Exp Ther. 2005;312(2):849-856.
  13. Nishijima C, Chiba T, Sato Y, Umegaki K. Nationwide online survey enables the reevaluation of the safety of Coleus forskohlii extract intake based on the adverse event frequencies. Nutrients. 2019;11(4):866.
  14. Virgona N, Taki Y, Yamada S, Umegaki K. Dietary Coleus forskohlii extract generates dose-related hepatotoxicity in mice. J Appl Toxicol. 2013;33(9):924-932.
Note

This page is informational and summarizes available evidence. It is not medical advice, a recommendation, or a substitute for guidance from a qualified clinician.