Hormone Support Protocol
FertirelinComplete Dosing & Administration Guide
A potent GnRH analog designed to support reproductive function in veterinary and research settings
Dose Range
25 micrograms-100 microgramsmg
Frequency
Once daily
Route
Intramuscular injection
Cycle Length
Ongoing/indefinite
Dosing
How much
do I take?
Timing
Best time to take
Administer Fertirelin at the same time each day (or on the same day each week for weekly injections). Many users prefer morning or evening administration. Pick a time you'll remember consistently.
With food?
Fertirelin injections can be given regardless of meal timing. However, if GI effects occur, administering on an empty stomach or with a light meal may help reduce discomfort.
If stacking
Fertirelin should be used as directed by your healthcare provider. If combining with other medications or supplements, discuss potential interactions with your provider. Avoid combining with compounds that have overlapping mechanisms unless specifically guided by a medical professional.
Adjusting Your Dose
Increase if
- +You've tolerated the current dose for the recommended period without significant side effects
- +Therapeutic goals haven't been met at the current dose level
- +Your healthcare provider recommends dose escalation based on your response
- +Lab work or clinical assessments support a higher dose
Decrease if
- -Side effects are bothersome or impacting daily life despite management strategies
- -You experience any signs of an adverse reaction
- -Lab results indicate the need for dose reduction
- -Your healthcare provider recommends a lower dose based on your response
Signs of right dose
- ✓Therapeutic goals being met with minimal side effects
- ✓Stable and consistent response to treatment
- ✓Lab values or clinical markers trending in the right direction
- ✓Good tolerance with manageable or absent side effects
Dosing Calculator
Calculate Your Exact Dose
Step 1: Peptide Weight
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The peptide weight is printed on the label
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Administration
How do I
use it?
Reconstitution
What you need
- •Fertirelin vial (lyophilized powder or solution)
- •Bacteriostatic water or sterile sodium chloride for reconstitution
- •Alcohol swabs for cleaning vial tops and injection sites
- •Appropriately sized syringes with fine-gauge needles (27-30 gauge)
- •Sharps disposal container
Injection
Route
Subcutaneous injection (into the fatty tissue just under the skin)—allows for consistent absorption and can be self-administered at home after proper training
Best sites
- •Abdomen (stomach area)—at least 2 inches from the belly button, most popular choice for self-injection
- •Front of thighs—middle to upper portion of the outer leg
- •Back of upper arm—outer area (may need assistance from another person)
Technique
- 1.Wash your hands thoroughly with soap and water before handling supplies
- 2.Clean the injection site with an alcohol swab and let it air dry completely
- 3.Pinch a fold of skin at the chosen injection site
- 4.Insert the needle at a 45-90 degree angle (depending on needle length and body composition)
- 5.Inject the medication slowly and steadily over 5-10 seconds
- 6.Release the skin fold and remove the needle, applying gentle pressure with a clean swab
- 7.Rotate injection sites to prevent tissue irritation or lipodystrophy
- 8.Dispose of the needle safely in a sharps container—never recap or reuse needles
Storage
Signs of degradation
Sample Daily Schedule
Safety
Is it
safe?
Safety Profile
Fertirelin is a GnRH agonist developed specifically for veterinary use in livestock, particularly cattle breeding and fertility management. The peptide has been safely used in veterinary medicine for over 40 years with a well-documented safety profile in animals. Important limitation: Fertirelin is NOT approved for human use. All safety and efficacy data comes from veterinary applications in cattle and limited laboratory research. Human safety data is minimal and extrapolation from veterinary use is problematic. The biphasic response (initial hormone surge followed by suppression) must be carefully managed in any application. Individual responses can vary significantly based on age, hormonal status, and concurrent medications.
Fertirelin's safety and efficacy data comes primarily from veterinary medicine, where it has been approved for cattle reproduction since 1981 in Japan. The peptide is 15-20 times more potent than natural GnRH at stimulating LH release. Human clinical data is extremely limited, with no FDA or EMA approval for any human indication.
Common Side Effects
Experienced by some users
Mild discomfort at treatment site
Some users experience mild discomfort, which is among the most commonly reported effects with Fertirelin. This typically resolves within a few days as the body adjusts.
Management: Apply ice if needed. Rotate treatment sites. These symptoms typically improve within the first week of use.
Transient hormone fluctuations
As a GnRH agonist, Fertirelin triggers an initial surge in FSH and LH (flare effect) within the first few days, followed by suppression. This biphasic response occurs in 60-80% of users and is expected. Animals may show increased reproductive behavior for 2-4 days before suppression begins.
Management: This is an expected physiologic response. Monitor for signs of exaggerated reproductive behavior. If using in breeding protocols, time applications accordingly. Discuss timing strategy with your veterinarian to optimize breeding outcomes.
Temporary behavioral changes in animals
Cattle and other livestock frequently show increased mounting behavior, vocalizations, and restlessness during the first 24-72 hours after injection, related to the initial hormone surge. These behavioral changes typically resolve as the flare effect subsides and suppression begins.
Management: Keep animals in secure enclosures during the first 48-72 hours post-injection. Provide adequate space and minimize handling stress. Separate animals if aggressive mounting occurs. These behaviors are temporary and expected, not a sign of adverse reactions.
Mild injection site reactions
Localized inflammation at the injection site occurs in approximately 15-20% of animals. This typically includes mild redness and slight induration that develops within hours and resolves within 3-7 days. Is rarely associated with infection or serious complications.
Management: Rotate injection sites between treatments to different areas of the neck or hindquarters. Use sterile injection technique. Apply ice packs if swelling is moderate. Monitor for signs of infection (increasing warmth, pus, fever). Most reactions resolve without intervention.
Short-term changes in appetite
Some animals experience decreased feed intake for 1-2 days immediately after Fertirelin injection, correlating with the behavioral changes from the initial hormone surge. Feed consumption typically normalizes by day 3-4 as hormone levels stabilize.
Management: Ensure animals have access to water and hay during the first few days. Continue offering feed even if intake is reduced; appetite usually returns spontaneously. Contact your veterinarian if appetite remains reduced beyond 4 days or if the animal appears distressed.
Temporary mood variations
Animals may appear more irritable or aggressive during the 24-72 hour period following injection due to elevated hormones. Restlessness and hyperreactivity are common. These mood changes correlate with the flare effect and typically resolve as LH suppression begins.
Management: Minimize stressful handling and procedures during the first 72 hours post-injection. Provide a calm environment. Avoid mixing treated and untreated animals if aggression is significant. These behavioral changes are temporary and expected with GnRH agonists.
Minimal systemic effects at therapeutic doses
Systemic side effects are uncommon at recommended veterinary doses (25-100 mcg). Most therapeutic responses are localized to reproductive and behavioral systems. Animals rarely show signs of systemic toxicity or off-target organ effects when using proper injection technique and staying within established dosing guidelines.
Management: Maintain strict adherence to veterinary dosing recommendations. Monitor general health status (appetite, activity, temperature) during the first week. Report any unexpected systemic signs (severe lethargy, vomiting, fever) to your veterinarian immediately, though these are rare.
Less Common
- •Occasional swelling at injection site
These typically resolve with continued use or dose adjustment.
Stop and Seek Help If
- ×Severe or worsening side effects that don't improve with dose adjustment or supportive care
- ×Signs of an allergic reaction—rash, hives, swelling, or difficulty breathing
- ×Your healthcare provider recommends discontinuation based on your clinical response
- ×Development of any new medical condition that may be contraindicated with Fertirelin
- ×Pregnancy or planning to become pregnant (unless specifically approved for use during pregnancy)
- ×Abnormal lab results or clinical markers that suggest adverse effects
Fertirelin should only be started, adjusted, or discontinued under medical supervision. This information is for educational purposes only and does not replace professional medical advice. Never stop a prescribed treatment without consulting your healthcare provider first, as abrupt discontinuation may have consequences.
Interactions
With other peptides
- ✓May be used together under medical guidance.
- ✓May be used together under medical guidance.
- ✓May be used together under medical guidance.
With medications
- !Dopamine agonists - Use with caution—discuss with your healthcare provider.
- !Other GnRH agonists without medical guidance - Use with caution—discuss with your healthcare provider.
- !Certain anticonvulsants - Use with caution—discuss with your healthcare provider.
With supplements
- ✓Multivitamins - Generally safe to take alongside Fertirelin. Space doses apart if taking oral formulations to ensure optimal absorption.
- ✓Electrolyte supplements - Helpful if experiencing any GI side effects that could lead to dehydration. Safe to combine.
Want the Full Picture?
View the complete Fertirelin research profile including mechanism of action, clinical studies, effectiveness timeline, and FAQ.
View Full Fertirelin Profile