L-Theanine During IVF: Safety and Recommendations
L-theanine should be discontinued 24 hours before egg retrieval based on perioperative surgical guidelines, though it can be safely continued during the ovarian stimulation phase of the IVF cycle. 1
Evidence-Based Recommendation
The Society for Perioperative Assessment and Quality Improvement (SPAQI) provides the only direct guideline addressing theanine in the context of procedures requiring anesthesia. 1 Their 2021 consensus statement specifically recommends holding theanine for 24 hours before surgery due to its dose-dependent blood pressure lowering effects. 1
Key Pharmacologic Considerations
L-theanine is a derivative of glutamate that causes dose-dependent decreases in blood pressure, which is the primary concern for procedures requiring anesthesia. 1
The compound has rapid metabolism and a short elimination half-life, which is why only a 24-hour hold period is necessary (unlike many supplements requiring 2-week discontinuation). 1
L-theanine may cause CNS depression, though this effect is mitigated by its rapid clearance from the system. 1
Practical Application to IVF Cycles
During Ovarian Stimulation (Safe to Continue)
There is no evidence suggesting L-theanine interferes with ovarian stimulation protocols, follicular development, or hormone levels during the IVF cycle. 1
The anxiolytic properties of L-theanine may actually be beneficial during the stressful stimulation phase, as stress reduction can support treatment adherence. 2, 3
Standard doses of 100-200 mg daily have demonstrated good safety profiles in clinical studies, with no reported reproductive toxicity. 4, 2
Before Egg Retrieval (Discontinue)
Stop L-theanine 24 hours before the scheduled egg retrieval procedure to avoid potential blood pressure effects during conscious sedation or general anesthesia. 1
The egg retrieval procedure requires anesthesia (typically conscious sedation or general anesthesia), making it equivalent to other surgical procedures covered by SPAQI guidelines. 1
Resume L-theanine after the procedure once the patient has recovered from anesthesia, as there are no contraindications for the post-retrieval or embryo transfer phases. 1
Important Clinical Caveats
What This Recommendation Does NOT Address
No specific data exists on L-theanine's effects on oocyte quality, fertilization rates, or embryo development, as this has never been studied in the context of assisted reproductive technology. 4, 5
The recommendation is based on perioperative safety considerations, not fertility-specific outcomes. 1
Safety Profile
L-theanine has demonstrated excellent tolerability in toxicity studies, even at doses exceeding typical supplementation levels. 4
No teratogenic effects or reproductive toxicity have been reported in animal studies, though human pregnancy data remains limited. 4, 5
The compound does not interact with gonadotropins, GnRH agonists/antagonists, or hCG trigger medications used in standard IVF protocols. 1
Clinical Algorithm
Weeks 1-2 of stimulation (until trigger): Continue L-theanine 100-200 mg daily 4, 2
Day of hCG trigger: Continue L-theanine 1
24 hours before egg retrieval: Discontinue L-theanine 1
Day of egg retrieval: Hold L-theanine 1
Post-retrieval recovery: Resume L-theanine once recovered from anesthesia 1
Embryo transfer cycle: No need to discontinue (transfer typically done without anesthesia or with minimal sedation) 1
Special Consideration for Anxiolysis
If the patient is taking L-theanine specifically for anxiety management during IVF, discuss alternative short-term anxiolytic strategies for the 24-hour hold period, as the SPAQI guidelines note that certain supplements with anxiolytic properties (like German chamomile, melatonin, and passionflower) can be continued perioperatively. 1
The brief 24-hour discontinuation is unlikely to cause rebound anxiety given L-theanine's mechanism of action and pharmacokinetics. 1, 3