Laxogenin (5-Alpha-Hydroxy Laxogenin Plant Steroid)

Smilax sieboldii / Hintonia latiflora
Evidence Level
Preliminary
1 Clinical Trial
3 Documented Benefits
1/5 Evidence Score

Laxogenin (5-alpha-hydroxy laxogenin) is a plant-derived spirostanol steroidal saponin found in the rhizome of Smilax sieboldii and related plants. It is marketed as a 'plant-based anabolic' due to its structural similarity to brassinosteroids — plant growth hormones that demonstrate protein synthesis stimulating activity in preliminary studies. Unlike synthetic anabolic steroids or prohormones, laxogenin does not convert to testosterone, DHT, or estrogen and does not appear to affect endogenous hormone levels — making it appealing for natural athletes seeking muscle-building support.

Studied Dose 50–100 mg/day laxogenin; limited human clinical data available; animal and cell studies suggest MPS enhancement; most evidence is anecdotal from athlete community
Active Compound 5-Alpha-hydroxy laxogenin (spirostanol steroidal saponin) from Smilax sieboldii or synthesized; typical supplement dose: 50–100 mg/day; bioavailability is an important consideration with this ingredient

Non-hormonal muscle protein synthesis support

Laxogenin is proposed to stimulate muscle protein synthesis through a brassinosteroid-analogous mechanism — activating protein synthesis signaling in muscle cells without engaging androgen receptors. The non-hormonal mechanism is its primary appeal for athletes in tested sports and those avoiding hormonal ingredients.

Anabolic support without testosterone effects

Unlike prohormones, SARMs, or anabolic steroids, laxogenin does not appear to affect testosterone, DHT, estrogen, LH, or FSH levels in preliminary studies — making it a legal, over-the-counter muscle-building option for natural athletes seeking stacking with other anabolic ingredients without hormonal disruption.

Cortisol inhibition and anti-catabolic effects

Some evidence suggests laxogenin may inhibit cortisol-mediated protein catabolism in muscle tissue — providing anti-catabolic protection during intense training or caloric restriction, complementing any direct anabolic MPS stimulation.

1

Brassinosteroid-analogous protein synthesis stimulation

Laxogenin's spirostanol steroidal structure is proposed to mimic brassinosteroids — plant steroid hormones that activate protein synthesis in plant cells through BES1/BZR1 transcription factor pathways. In animal models, brassinosteroid administration increases skeletal muscle mass through pathways that may parallel animal steroid signaling without engaging androgen receptors. The specific molecular target in human muscle cells remains incompletely characterized, reflecting the limited human research base for this ingredient.

1
Laxogenin — Limited Clinical Evidence
PubMed

No published human double-blind RCTs available for laxogenin as of 2025. Evidence base consists of animal studies, in vitro research, and widespread anecdotal athlete experience.

Animal and cell models primarily. No published human RCTs.

Animal studies show increased muscle protein synthesis. In vitro data suggests mTOR-independent protein synthesis stimulation. Human evidence is primarily anecdotal from athlete community reporting muscle hardening and recovery benefits. Evidence level reflects absence of human clinical trials — this is an area where controlled human research is needed.

Common Potential side effects

Generally reported as well tolerated in athlete community
Limited formal safety data — no long-term toxicology studies published
Not for use by individuals under 18 or during pregnancy
Variable purity and content in commercial products — quality sourcing essential

Important Drug interactions

No established drug interactions — limited data available
Steroid-sensitive conditions — theoretical concern given steroidal structure; consult physician