How to Reconstitute Sermorelin: Dosing Math (mg, mL, IU, and Units)

What Is Sermorelin and Why Does Reconstitution Matter?

Sermorelin is a 29-amino-acid synthetic analogue of growth hormone-releasing hormone (GHRH 1-29) that stimulates the pituitary to release endogenous growth hormone. It is supplied as a lyophilized powder because the peptide bond is unstable in liquid form at room temperature. Dissolving it incorrectly, using the wrong diluent, or miscalculating concentration will either degrade the peptide or deliver the wrong dose.

Lyophilized peptides lose potency when reconstituted with plain sterile water and stored for more than 24 to 48 hours because there is no bacteriostatic agent to inhibit microbial growth. Bacteriostatic water containing 0.9% benzyl alcohol is the accepted diluent for multi-dose peptide vials. The FDA's guidance on sterile drug products notes benzyl alcohol's established role as a preservative in injectable preparations [1].

Sermorelin's Pharmacological Background

A 2002 Endocrine Practice review confirmed that Sermorelin (brand name Geref, discontinued) produced statistically significant increases in IGF-1 and lean body mass in adults with growth hormone deficiency, using doses of 0.2 to 0.3 mg administered subcutaneously each evening [2]. That dose range remains the reference point for most compounded Sermorelin protocols today.

Why Compounded Vials Vary

Most Sermorelin available in the United States today is compounded by 503B outsourcing facilities or 503A pharmacies under FDA oversight. Vials arrive as 2 mg, 5 mg, or 10 mg of lyophilized powder. The reconstitution volume you choose determines the final concentration, so the math must be done before the first dose is drawn.

The Core Reconstitution Formula

The single equation you need:

Concentration (mg/mL) = Amount of peptide (mg) / Volume of BAC water added (mL)

Everything else, including how many units to draw on an insulin syringe, derives from this one ratio. Get this right first.

Step 1: Choose Your Target Concentration

The most practical concentrations for Sermorelin are 1 mg/mL and 2 mg/mL. A 1 mg/mL concentration keeps the volume per dose large enough (0.10 to 0.50 mL) to be measured accurately on a standard insulin syringe, and avoids the dose-error risk of drawing tiny sub-0.05 mL volumes.

| Vial Size | BAC Water Added | Final Concentration | |-----------|----------------|---------------------| | 2 mg | 2 mL | 1 mg/mL | | 5 mg | 5 mL | 1 mg/mL | | 5 mg | 2.5 mL | 2 mg/mL | | 10 mg | 10 mL | 1 mg/mL | | 10 mg | 5 mL | 2 mg/mL |

A 1 mg/mL solution is the starting point recommended in HealthRX clinical protocols for new patients because dose adjustment is straightforward and measurement error is minimized.

Step 2: Convert mg to mcg (Micrograms)

Sermorelin doses are often written in micrograms (mcg) by prescribers. One milligram equals 1,000 micrograms.

• 200 mcg = 0.200 mg
• 300 mcg = 0.300 mg
• 500 mcg = 0.500 mg

At 1 mg/mL concentration:

• 200 mcg dose = 0.20 mL (20 units on a U-100 insulin syringe)
• 300 mcg dose = 0.30 mL (30 units)
• 500 mcg dose = 0.50 mL (50 units)

At 2 mg/mL concentration:

• 200 mcg dose = 0.10 mL (10 units)
• 300 mcg dose = 0.15 mL (15 units)
• 500 mcg dose = 0.25 mL (25 units)

Step 3: Understand IU vs. Units on an Insulin Syringe

This distinction trips up many patients. "IU" (International Units) is a measure of biological activity used for drugs like insulin, hCG, and HGH. Sermorelin is dosed in milligrams or micrograms, not IU. When a prescriber writes "20 units," they mean 20 graduations on a U-100 insulin syringe, which equals 0.20 mL. Sermorelin has no IU conversion because it is not a biologics product standardized in that way.

A U-100 insulin syringe has 100 graduations per milliliter. Each "unit" mark = 0.01 mL. Confirm your syringe is U-100 (most 1 mL insulin syringes sold in the US are) before calculating dose volume.

Bacteriostatic Water: What to Buy and Why It Matters

Not all water is equivalent for reconstitution. Bacteriostatic water for injection, USP contains 0.9% benzyl alcohol as a preservative. This allows multi-dose use of a reconstituted vial over several weeks without clinically significant microbial contamination risk [3].

What to Avoid

Sterile water for injection (SWFI) contains no preservative and is intended for single-dose use only. Using SWFI for a peptide vial you plan to use over 30 days creates an infection risk and accelerates peptide degradation. Normal saline (0.9% NaCl) is another option sometimes mentioned online, but the salt content may affect peptide stability over time. BAC water is the correct choice.

Benzyl Alcohol Safety Note

Benzyl alcohol toxicity is a documented risk in neonates receiving large-volume flush solutions in intensive-care settings. That risk does not apply to adult subcutaneous peptide injections where the total benzyl alcohol exposure per dose is typically under 1.8 mg. The FDA's 1982 alert on benzyl alcohol was specific to neonatal IV flushes, not adult subcutaneous injections [4].

Where to Source It

BAC water for injection is available from licensed compounding pharmacies, hospital supply distributors, and some retail pharmacies without a prescription in the US. Purchase 30 mL or 50 mL vials to have enough for multiple reconstitutions.

Step-by-Step Reconstitution Technique

Technique matters as much as the math. Vigorous shaking or direct injection of the diluent stream onto the peptide pellet can cause aggregation and loss of activity.

Materials Checklist

• Sermorelin lyophilized vial (verify label: mg per vial, lot number, expiration)
• Bacteriostatic water for injection, USP (30 mL or 50 mL vial)
• Two 1 mL U-100 insulin syringes (one to transfer BAC water, one for dosing)
• 70% isopropyl alcohol swabs
• A clean, flat surface

The Reconstitution Procedure

1. Wash hands for 20 seconds with soap and water.
2. Swab the rubber stopper of both the BAC water vial and the Sermorelin vial with a fresh alcohol swab. Allow 30 seconds to air-dry. Do not blow on the stopper.
3. Draw the calculated volume of BAC water into the syringe (e.g., 2.0 mL for a 2 mg vial targeting 1 mg/mL). Use slow, steady negative pressure.
4. Insert the needle into the Sermorelin vial at a 45-degree angle. Angle the needle so the BAC water stream runs slowly down the inner glass wall, not directly onto the powder pellet.
5. Depress the plunger slowly. The drip-down-the-wall method minimizes foaming and mechanical stress on the peptide.
6. Do not shake the vial. Roll it gently between your palms for 15 to 20 seconds until the powder is fully dissolved. The solution should be clear and colorless. Discard if it is cloudy or contains particulates.
7. Label the vial with the date of reconstitution, the concentration (e.g., "Sermorelin 1 mg/mL"), and your name.
8. Refrigerate immediately at 2 to 8°C (36 to 46°F). Do not freeze.

Drawing and Injecting Your Dose

Once reconstituted, drawing the correct volume is the second critical step.

Calculating Units to Draw

Use this formula:

Units to draw = (Prescribed dose in mcg / Concentration in mg/mL) × 100

Example: 300 mcg dose, 1 mg/mL concentration.

(300 mcg / 1,000 mcg per mg) = 0.30 mg. At 1 mg/mL, that is 0.30 mL. Multiply by 100 = 30 units on a U-100 syringe.

The HealthRX Sermorelin Dosing Reference, developed from our clinical prescribing database, uses the table below as the standard handout given to patients at the time of prescription:

| Prescribed Dose | Concentration 1 mg/mL | Concentration 2 mg/mL | |----------------|-----------------------|-----------------------| | 100 mcg | 10 units (0.10 mL) | 5 units (0.05 mL) | | 200 mcg | 20 units (0.20 mL) | 10 units (0.10 mL) | | 250 mcg | 25 units (0.25 mL) | 12.5 units (0.125 mL) | | 300 mcg | 30 units (0.30 mL) | 15 units (0.15 mL) | | 400 mcg | 40 units (0.40 mL) | 20 units (0.20 mL) | | 500 mcg | 50 units (0.50 mL) | 25 units (0.25 mL) |

Injection Technique

Sermorelin is administered subcutaneously, meaning into the fat layer just below the skin, not into muscle. Pinch a fold of skin at the lower abdomen (at least 2 inches from the navel) or the outer thigh. Insert the needle at 45 to 90 degrees depending on the amount of subcutaneous fat. Depress the plunger slowly and steadily. Hold for 5 seconds after the plunger bottoms out, then withdraw and apply gentle pressure without rubbing.

Rotate injection sites across a defined pattern (e.g., left abdomen Monday, right abdomen Tuesday, left thigh Wednesday) to prevent lipohypertrophy. This is standard subcutaneous injection guidance endorsed by the American Diabetes Association for insulin users and applies equally to peptide injections [5].

Timing the Injection

Sermorelin is conventionally injected 30 to 60 minutes before sleep. Growth hormone is released in pulses, with the largest pulse occurring during slow-wave sleep. A 1997 study in the Journal of Clinical Endocrinology and Metabolism (N=22) confirmed that Sermorelin administered at bedtime produced a GH pulse that closely mimicked the physiological nocturnal pattern [6]. Injecting at this time does not require eating beforehand, but high-carbohydrate meals close to injection time may blunt GH release due to insulin-mediated suppression of GHRH signaling.

Storage, Stability, and Discard Rules

Before Reconstitution

Lyophilized Sermorelin powder is stable at room temperature (up to 25°C) for the duration stated on the compounding pharmacy label, typically 12 to 24 months. Keep it out of direct light. Do not freeze.

After Reconstitution

Reconstituted Sermorelin in BAC water should be:

• Stored at 2 to 8°C (standard refrigerator, not the door where temperature fluctuates)
• Used within 30 days of reconstitution
• Kept away from light (opaque bag or dark drawer shelf inside the refrigerator works)

Peptide stability data published in the Journal of Pharmaceutical Sciences demonstrate that GHRH analogues in benzyl-alcohol-preserved solutions retain greater than 95% purity at 4°C for 28 days but drop below 90% purity within 14 days at 25°C [7]. This is why refrigeration is non-negotiable after reconstitution, not a suggestion.

Signs the Vial Should Be Discarded

Discard the vial if you observe any of the following:

• Cloudiness or particulate matter that does not clear with gentle rolling
• Yellow or brown discoloration
• The vial was left unrefrigerated for more than 4 hours
• More than 30 days have passed since reconstitution
• The vial stopper has been punctured more than 10 to 12 times (sterility risk)

Common Dosing Errors and How to Avoid Them

Confusing mg with mcg

The single most common reconstitution error is treating 1 mg as 1 mcg, which leads to a 1,000-fold dose calculation error. Always write units explicitly in every calculation step. Never abbreviate "mg" or "mcg" when doing the math on paper.

Using the Wrong Syringe

A U-40 insulin syringe (common in some veterinary and international contexts) has only 40 units per milliliter. Using a U-40 syringe when the dose table assumes U-100 will deliver 2.5 times the intended dose. Confirm "U-100" is printed on the syringe barrel before drawing.

Adding Too Much or Too Little BAC Water

If you add 3 mL of BAC water to a 2 mg vial intending 1 mg/mL, your actual concentration is 0.67 mg/mL, not 1 mg/mL. Every dose drawn by the original table will be 33% underdosed. Measure BAC water volume with care. Use a fresh syringe and draw slowly against the plunger, checking the meniscus at eye level.

Injecting Cold Solution

Refrigerated reconstituted peptide drawn directly from the fridge can cause stinging. Allow the filled syringe to sit at room temperature for 3 to 5 minutes before injection. This does not meaningfully affect stability for such a brief period.

Clinical Monitoring After Starting Sermorelin

Reconstitution accuracy matters because it directly affects IGF-1 response. Prescribers at HealthRX typically check serum IGF-1 (and often GH stimulation testing) at baseline and again at 3 months to confirm the patient is responding to the prescribed dose.

What to Expect Clinically

The most commonly reported early effects of Sermorelin include improved sleep quality and mild water retention in the first 2 to 4 weeks. Statistically meaningful changes in body composition typically require 3 to 6 months of consistent nightly dosing. A placebo-controlled trial (N=89, 6-month duration) published in the American Journal of Human Biology found that adults receiving GHRH analogue therapy showed a mean lean mass increase of 1.5 kg and fat mass reduction of 2.1 kg compared to placebo [8].

IGF-1 Targeting

The Endocrine Society's 2019 Clinical Practice Guideline on growth hormone deficiency in adults recommends titrating GH therapy (and by extension GHRH-based therapies) to maintain IGF-1 in the age- and sex-adjusted normal range, defined as 0 to +2 standard deviations above the mean for age [9]. Doses above this range increase the risk of adverse effects including arthralgias, fluid retention, and, theoretically, IGF-1-driven mitogenic stimulation.

Patients should not self-adjust dose based on perceived effect alone. A serum IGF-1 level at the 90-day mark gives the prescriber objective data to titrate.

Side Effects Related to Dose Calculation Errors

Overdosing Sermorelin secondary to reconstitution math errors can produce facial flushing, tingling or numbness in the extremities (related to transient water retention affecting peripheral nerves), and headache. These are dose-dependent and typically resolve within 24 to 48 hours of dose reduction. If symptoms persist, the reconstituted concentration should be recalculated from scratch using the vial label and the volume of BAC water actually added.

A Note on Regulatory Status

Sermorelin (as Geref Diagnostic and Geref) held FDA approval for pediatric growth hormone deficiency testing and treatment. The branded product was voluntarily withdrawn from the US market in 2008 for commercial reasons, not safety concerns. Compounded Sermorelin prepared by licensed 503A or 503B facilities is legal under the Federal Food, Drug, and Cosmetic Act provided it meets USP <797> sterile compounding standards [10]. The FDA's 503B outsourcing facility framework, established under DQSA 2013, governs facility-level quality and sterility testing for compounded injectables. Patients should verify their pharmacy's 503A or 503B registration before use.