Thymalin dosage:
5–10 mg daily, short-cycle protocol.
The standard thymalin dosage is 5–10 mg administered once daily by subcutaneous or intramuscular injection for 5–10 consecutive days, constituting one treatment cycle. This is the dosing regimen validated across four decades of clinical use in Russia and Eastern Europe for immune restoration, anti-aging, and post-illness recovery. Unlike peptides that require continuous daily administration, thymalin peptide uses a short-cycle design — a brief burst of administration triggers a cascade of immune reconstitution and gene expression changes that persist for weeks to months after the cycle ends. Most protocols call for 2–4 cycles per year, timed seasonally or around periods of immune stress. This guide covers the complete thymalin dosage protocol: standard dosing, reconstitution, injection technique, cycle timing, zinc dependency, and the clinical regimens used in the published research.
Thymalin dosage: the 5–10 mg daily short-cycle standard.
Thymalin dosage follows a fundamentally different paradigm from most peptides. Where compounds like BPC-157 or tesamorelin require weeks or months of continuous daily injections, thymalin peptide is administered in short bursts — typically 5–10 mg per day for 5–10 consecutive days — and then discontinued. The immune reconstitution triggered by this brief exposure persists for months because thymalin acts at the level of gene expression and cellular differentiation, not transient receptor activation. Once T-cell progenitors have been stimulated to differentiate and mature, the resulting immune cells remain functional for their natural lifespan.
The 10 mg daily dose represents the upper end of the therapeutic range and is used in clinical settings for active immune deficiency, post-surgical recovery, and acute infection support. The 5 mg daily dose is more common for general immune maintenance, seasonal prophylaxis, and anti-aging applications. Preventive protocols documented by RuPharma use 1–10 mg for 3–5 days, suggesting that even shorter cycles at lower doses provide measurable immune benefit.
Thymalin is administered via either subcutaneous (SubQ) or intramuscular (IM) injection. Both routes are clinically documented. SubQ injection into the abdominal fat fold is more common in the biohacking community due to ease of self-administration. IM injection into the deltoid or gluteal muscle was the standard route in Russian clinical settings and may produce slightly faster systemic absorption, though clinical outcomes between the two routes have not been formally compared.
Timing within the day is not strictly prescribed. Thymalin peptide does not interact with the circadian GH axis the way growth hormone secretagogues do, so there is no fasting requirement and no meal timing consideration. Morning administration is conventional simply for consistency.
Thymalin cycle: frequency, duration, and seasonal timing.
Most thymalin protocols call for 2–4 cycles per year, spaced roughly 3–6 months apart. The rationale is rooted in thymic biology: the immune reconstitution triggered by one cycle of thymalin peptide has a biological half-life of several months, after which thymic output gradually returns to its pre-treatment baseline as the effects of the peptide on gene expression attenuate. Repeating cycles maintains the elevated immune function over time.
Seasonal timing is common. Many practitioners schedule thymalin cycles in early autumn (before cold and flu season) and late winter (to boost immune recovery after the winter pathogen load). Athletes and individuals under chronic physical stress may add a third cycle post-competition season or after a period of overtraining, when immune suppression from accumulated cortisol exposure is highest.
The short-cycle design is one of thymalin's practical advantages over continuous-administration peptides. A full year of thymalin therapy requires only 20–40 days of injections total, compared to 365 days for a compound like tesamorelin or ipamorelin. This makes thymalin peptide one of the lowest-burden peptide protocols available in terms of injection frequency and total dosing volume.
| Protocol | Daily dose | Cycle length | Frequency | Use case |
|---|---|---|---|---|
| Clinical standard | 5–10 mg | 5–10 days | 2–4× per year | Immune deficiency, post-illness recovery |
| Anti-aging / longevity | 5–10 mg | 10 days | 2× per year | Thymic restoration, geroprotection |
| Preventive / seasonal | 1–10 mg | 3–5 days | 2–3× per year | Pre-flu season, general immune support |
| Post-surgical / acute | 10 mg | 5–10 days | As needed | Immune recovery after surgery or infection |
| Longevity stack (with epithalon) | 10 mg each | 10 days | 2× per year | Combined thymic + pineal bioregulation |
Thymalin reconstitution: how to prepare and store thymalin peptide.
Thymalin is supplied as a lyophilized (freeze-dried) powder in sterile vials, typically in 10 mg vials. Reconstitution follows the same principles as other injectable peptides, though the short cycle length means fewer total reconstitution events per year.
Step 1: Sterilization. Wipe the rubber stoppers of both the thymalin vial and the bacteriostatic water (BAC water) vial with a 70% isopropyl alcohol swab. Allow 30 seconds to air dry.
Step 2: Draw diluent. Using an insulin syringe, draw 1 mL of bacteriostatic water. For a 10 mg vial, 1 mL of BAC water yields a concentration of 10 mg/mL — each 0.1 mL (10 units on a U-100 syringe) equals 1 mg of thymalin.
Step 3: Reconstitute. Insert the needle into the thymalin vial at an angle and drip the water slowly down the glass wall. Do not inject directly onto the powder pellet. Do not shake — gently roll the vial between your palms until the solution is clear.
Step 4: Storage. Reconstituted thymalin should be refrigerated at 2–8°C and used within 10–14 days. Since a typical thymalin cycle is 5–10 days, one reconstituted vial aligns closely with one complete cycle. Unreconstituted lyophilized thymalin can be stored at -20°C for long-term stability or refrigerated at 2–8°C for shorter-term storage.
Zinc dependency
Thymalin peptide efficacy is dependent on adequate zinc status. Zinc is a required cofactor for thymic function and T-cell maturation. If zinc levels are insufficient, thymalin's immunomodulatory effects will be substantially blunted. Supplementing with 15–30 mg of elemental zinc daily (zinc picolinate or zinc bisglycinate for bioavailability) during and around thymalin cycles is standard protocol. This is one of the few peptide protocols where a specific mineral co-factor is clinically documented as required for efficacy.
Thymalin dosage FAQ.
What is the standard thymalin dose?
The standard thymalin dosage is 5–10 mg administered once daily by subcutaneous or intramuscular injection for 5–10 consecutive days. This constitutes one treatment cycle. The dose is the same regardless of body weight in the published clinical literature, though some practitioners titrate to the lower end (5 mg) for lighter individuals or first-time users. Cycles are repeated 2–4 times per year for sustained immune benefit.
How many units is 10 mg of thymalin?
If reconstituted at 10 mg/mL (10 mg vial + 1 mL bacteriostatic water), 10 mg of thymalin equals 100 units on a U-100 insulin syringe (the full syringe). A 5 mg dose at the same concentration equals 50 units (0.5 mL). If you reconstitute with 2 mL instead of 1 mL, the concentration drops to 5 mg/mL and a 10 mg dose requires the full 2 mL — which exceeds most insulin syringe capacities, so 1 mL reconstitution is standard for thymalin.
How long is a thymalin cycle?
A standard thymalin cycle is 5–10 consecutive days of daily injections, followed by discontinuation. The immune restoration effects persist for weeks to months after the cycle ends because thymalin acts on gene expression and T-cell differentiation rather than transient receptor signaling. Most protocols repeat the cycle every 3–6 months, totaling 2–4 cycles per year. A single 10 mg vial provides one complete cycle at the 10 mg daily dose for 10 days if reconstituted at 10 mg/mL and dosed at 1 mg/day — or 1 day at the full 10 mg dose.
Can thymalin be taken with other peptides?
Yes. The most studied thymalin stack is with epithalon, the pineal peptide bioregulator. The Khavinson & Morozov 6-year longevity trial used thymalin and epithalon together and produced the most significant mortality reduction data in peptide research. Thymalin is also stacked with BPC-157 (for combined immune + repair effects), thymosin alpha-1 (for intensified T-cell support), and vilon/crystagen (other short peptide bioregulators from the Khavinson research program). See the thymalin vs epithalon guide for detailed stack protocols.
Does thymalin need to be injected?
Yes. Thymalin peptide is a polypeptide complex that would be destroyed by digestive enzymes if taken orally. Subcutaneous and intramuscular injection are the two documented administration routes. Subcutaneous injection into the abdominal fat fold is the most common self-administration method. Intramuscular injection was the standard in Russian clinical settings. There is no oral, nasal, or sublingual form of thymalin with documented efficacy.
Why is zinc important for thymalin?
Zinc is an essential cofactor for thymic function. The thymus gland requires zinc for T-cell maturation, and zinc deficiency is independently associated with accelerated thymic involution and impaired immune function. Thymalin peptide works by stimulating thymic activity, but if the raw material (zinc) required for that activity is missing, the stimulation produces a blunted response. Supplementing 15–30 mg of elemental zinc daily during thymalin cycles is standard practice and is one of the few cases in peptide therapy where a specific mineral supplement is documented as necessary for full efficacy.