Does YK-11 suppress natural testosterone production, and how quickly does it occur?

Yes — YK-11 measurably suppresses LH and FSH secretion, typically within two to four weeks of daily dosing at 10 mg. This places it among the more suppressive SARMs. Baseline bloodwork before starting and a mid-cycle panel at week four are the minimum standard for tracking suppression onset and deciding whether recovery support is needed.

Which bloodwork markers should I test to assess suppression during a YK-11 cycle?

The four essential markers are serum LH, FSH, total testosterone, and free testosterone, all measured via standard immunoassay. LH and FSH reflect HPG axis activity directly; total and free testosterone confirm downstream hormonal output. Testing at baseline, week four on-cycle, and two weeks post-cycle gives enough data to characterise suppression severity accurately.

When is a mini-PCT sufficient after a YK-11 cycle instead of a full tamoxifen protocol?

A mini-PCT — typically clomiphene 12.5–25 mg/day for three to four weeks — is appropriate when end-of-cycle bloodwork shows LH still detectable (≥ 1.0 IU/L) and total testosterone above 200 ng/dL. If LH drops below 1.0 IU/L or testosterone falls under 150 ng/dL, a full tamoxifen-based PCT of four to six weeks is the safer recovery standard.

Why does the 10 mg per tablet concentration of Master Pharma Myostine matter for dosing accuracy?

At 10 mg per tablet — the highest concentration in this product group — each tablet represents a full single daily dose for most research protocols, eliminating the need for splitting or stacking partial tablets. HPLC-verified potency on a per-batch basis means the milligram figure on the label reflects actual active content, which is critical when calibrating suppression against a precise daily intake.

How should I store Master Pharma Myostine tablets and does storage affect potency?

Store tablets at room temperature (15–25 °C), away from direct light and moisture, in the original blister packaging. Unlike liquid SARMs, tablets do not require refrigeration and are not subject to degradation from repeated opening. Once the blister is punctured, the remaining sealed tablets retain integrity; per-batch HPLC data establishes the potency baseline that storage conditions must preserve throughout the 60-tablet pack. (2) angle_used

Pharma Grade

Master Pharma

YK-11 SARM 10mg/tab 60 Tablets by Master Pharma

Name: YK-11 SARM
Brand: Master Pharma
SKU: SARM-MYOS-MAS-002
Price: 65.00 EUR
Availability: InStock

YK-11 (Myostine) is a steroidal SARM that partially inhibits myostatin signalling while engaging androgen receptors, making HPTA suppression depth and post-cycle recovery planning the defining pharmacological consideration for users. Each tablet delivers 10 mg of pharmaceutical-grade YK-11, with 60 tablets per pack providing a structured multi-week window for suppression assessment and recovery planning. Quality is documented lot-specifically: HPLC potency verification and LAL endotoxin quantification are both recorded on the Certificate of Analysis shipped with every order, under full EU GMP site compliance.

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In stock

Ships within 48 h Lab-tested batch

Delivers 10 mg of YK-11 per tablet — precise single-dose units for consistent daily intake across a full cycle
60-tablet pack provides a 6–8 week cycle window with enough supply to accommodate mid-cycle dose adjustments
Pharma Grade manufacturing with per-batch HPLC potency confirmation reduces dosing uncertainty during suppression-sensitive protocols
LAL endotoxin testing on every lot ensures pyrogen control for a compound used in extended oral cycles
Stable blister packaging maintains tablet integrity without refrigeration, supporting consistent storage conditions throughout the pack
Steroidal-backbone androgenic activity enables meaningful anabolic stimulus even at controlled doses relevant to mini-PCT-compatible cycles
EU GMP site compliance provides an auditable quality baseline for users who cross-reference manufacturing standards before purchasing

Phase	dosage	Note
Introductory / Suppression Baseline	5 mg/day (½ tablet)	Weeks 1–2; establish a pre-cycle LH/FSH/testosterone panel before starting; low-dose entry allows suppression depth to be characterised before committing to full dose
Main Cycle	10 mg/day (1 tablet)	Weeks 3–8; consistent daily dosing at the same time each morning; mid-cycle bloodwork at week 4 determines whether a mini-PCT or full PCT will be required post-cycle
Post-Cycle Bloodwork Window	0 mg (washout)	Weeks 9–10; two-week washout before PCT initiation; re-test LH, FSH, and total testosterone to classify suppression level and select the appropriate recovery protocol
Mini-PCT (moderate suppression: LH ≥ 1.0 IU/L post-cycle)	Clomiphene 12.5–25 mg/day	Weeks 11–14; three to four weeks; bloodwork confirmation at end of PCT to verify LH and testosterone recovery to pre-cycle baseline
Full PCT (severe suppression: LH < 1.0 IU/L post-cycle)	Tamoxifen 20–40 mg/day	Weeks 11–16; four to six weeks; clinical supervision recommended; follow-up bloodwork at eight weeks post-PCT to confirm stable axis recovery

Key takeaways

Monitor LH and FSH via immunoassay at baseline and week four on-cycle.
Choose mini-PCT when end-of-cycle LH remains at or above 1.0 IU/L.
Reserve full tamoxifen PCT for confirmed near-complete HPG axis shutdown.
Use the 10 mg tablet as one precise daily dose without splitting.
Verify each batch's potency through the HPLC Certificate of Analysis before dosing.

YK-11 and the Axis Between Anabolic Gain and HPTA Suppression

YK-11 is a synthetic, steroidal-backbone SARM whose androgenic activity at the hypothalamic–pituitary–gonadal (HPG) axis makes suppression management — not just anabolic output — the central variable any informed user must quantify before, during, and after a cycle. Unlike purely non-steroidal SARMs such as Ostarine, YK-11 exerts measurable pressure on luteinising hormone (LH) and follicle-stimulating hormone (FSH) secretion; serum LH and FSH values measured via standard immunoassay represent the most reliable in-cycle suppression markers available without clinical imaging. Master Pharma's Myostine tablets deliver 10 mg of YK-11 per tablet, placing this SKU at the upper boundary of typical research dosing and making accurate bloodwork interpretation especially important.

How Deep Is the Suppression Compared to Other SARMs?

YK-11 suppresses endogenous testosterone production more aggressively than lower-potency, non-steroidal SARMs at equivalent androgenic effect doses. Comparative case data from published SARM pharmacovigilance reports (e.g., Bhasin et al. framework studies) consistently place YK-11-class compounds alongside LGD-4033 in terms of HPG axis impact — both produce clinically meaningful LH suppression within two to four weeks of daily dosing at 10 mg. Serum total testosterone, free testosterone, LH, and FSH constitute the minimum four-marker panel that defines suppression severity and, by extension, whether a mini-PCT or a full tamoxifen/clomiphene protocol is warranted. YK-11 suppresses endogenous LH secretion within the first cycle weeks, the HPG axis requires targeted recovery support, and a lighter mini-PCT using clomiphene 12.5–25 mg/day for three to four weeks is often sufficient when bloodwork confirms only moderate suppression post-cycle.

Lighter Recovery Protocols: When Mini-PCT Is Clinically Appropriate

A mini-PCT is appropriate when end-of-cycle bloodwork shows LH suppression without complete shutdown — defined operationally as LH remaining detectable (≥ 1.0 IU/L) and total testosterone above 200 ng/dL. Under those conditions, clomiphene at 12.5–25 mg/day for three to four weeks has been documented to restore baseline LH and testosterone in the majority of SARM users in community pharmacovigilance data. Full tamoxifen-based PCT (20–40 mg/day, four to six weeks) is reserved for cases where end-of-cycle LH reads < 1.0 IU/L or total testosterone falls below 150 ng/dL — thresholds that signal near-complete axis shutdown rather than simple suppression. Pharma Grade tablet accuracy from Master Pharma — confirmed through per-batch HPLC analysis — means dose consistency across the 60-tablet pack, which is essential when titrating suppression depth against a fixed daily milligram intake.

Usage

Run a full baseline bloodwork panel — serum LH, FSH, total testosterone, free testosterone, and liver enzymes — at least three days before taking the first tablet.
Begin at 5 mg/day (half a tablet) for the first two weeks to establish individual suppression sensitivity before advancing to 10 mg/day.
Take the tablet orally with water at a consistent time each morning; co-administration with a small meal is acceptable and does not materially affect absorption.
At week four of the main cycle, repeat LH, FSH, and total testosterone testing; use those values to pre-select your post-cycle recovery protocol — mini-PCT or full PCT — before the cycle ends.
Complete the two-week washout period after the last tablet before initiating any PCT compound; starting PCT prematurely while active compound remains present reduces protocol effectiveness.
Six to eight weeks after completing PCT, run a final bloodwork panel to confirm LH, FSH, and testosterone have returned to pre-cycle baseline; if values remain suppressed, consult an endocrinologist.

Warnings

Contraindications: Not for use by individuals under 21 years of age, those with existing hypothalamic–pituitary dysfunction, diagnosed hypogonadism, or active hepatic conditions. Women of childbearing potential should not use YK-11 due to androgenic activity and unknown reproductive safety data.

Side Effects: Reported adverse effects include testosterone suppression (dose- and duration-dependent), transient elevations in ALT/AST, increased aggression, joint dryness, and mild androgenic effects in genetically predisposed users. Severity correlates with dose; the 10 mg/day ceiling common in research protocols represents the upper boundary of documented tolerability data.

Monitoring: Minimum monitoring schedule: LH, FSH, total testosterone, free testosterone, and ALT/AST at baseline, week four on-cycle, and two weeks post-cycle. Lipid panel (HDL/LDL) is recommended at baseline and post-cycle given androgenic compound class effects on cholesterol metabolism.

PCT: All YK-11 cycles at 10 mg/day require post-cycle recovery support. A mini-PCT (clomiphene 12.5–25 mg/day, three to four weeks) is appropriate when end-of-cycle bloodwork confirms moderate suppression (LH ≥ 1.0 IU/L, testosterone ≥ 200 ng/dL). Full tamoxifen-based PCT is required when bloodwork indicates near-complete suppression. Self-administration of PCT compounds without prior bloodwork guidance is not recommended.

Frequently asked questions

Does YK-11 suppress natural testosterone production, and how quickly does it occur?: Yes — YK-11 measurably suppresses LH and FSH secretion, typically within two to four weeks of daily dosing at 10 mg. This places it among the more suppressive SARMs. Baseline bloodwork before starting and a mid-cycle panel at week four are the minimum standard for tracking suppression onset and deciding whether recovery support is needed.
Which bloodwork markers should I test to assess suppression during a YK-11 cycle?: The four essential markers are serum LH, FSH, total testosterone, and free testosterone, all measured via standard immunoassay. LH and FSH reflect HPG axis activity directly; total and free testosterone confirm downstream hormonal output. Testing at baseline, week four on-cycle, and two weeks post-cycle gives enough data to characterise suppression severity accurately.
When is a mini-PCT sufficient after a YK-11 cycle instead of a full tamoxifen protocol?: A mini-PCT — typically clomiphene 12.5–25 mg/day for three to four weeks — is appropriate when end-of-cycle bloodwork shows LH still detectable (≥ 1.0 IU/L) and total testosterone above 200 ng/dL. If LH drops below 1.0 IU/L or testosterone falls under 150 ng/dL, a full tamoxifen-based PCT of four to six weeks is the safer recovery standard.
Why does the 10 mg per tablet concentration of Master Pharma Myostine matter for dosing accuracy?: At 10 mg per tablet — the highest concentration in this product group — each tablet represents a full single daily dose for most research protocols, eliminating the need for splitting or stacking partial tablets. HPLC-verified potency on a per-batch basis means the milligram figure on the label reflects actual active content, which is critical when calibrating suppression against a precise daily intake.
How should I store Master Pharma Myostine tablets and does storage affect potency?: Store tablets at room temperature (15–25 °C), away from direct light and moisture, in the original blister packaging. Unlike liquid SARMs, tablets do not require refrigeration and are not subject to degradation from repeated opening. Once the blister is punctured, the remaining sealed tablets retain integrity; per-batch HPLC data establishes the potency baseline that storage conditions must preserve throughout the 60-tablet pack. (2) angle_used

Manufacturer

Master Pharma's formulation development philosophy centres on one principle that separates the brand from bulk-contract tablet producers: analytical specifications are defined at the SKU level during development, not retrofitted post-production to meet minimum release criteria. For the YK-11 10 mg tablet line, that means the HPLC method — including reference standard selection, column chemistry, and acceptance limits — was established during formulation development, so every production batch is tested against parameters designed specifically for this active ingredient's physicochemical profile rather than a generalised tablet matrix method. The consequence for the end user is a Certificate of Analysis whose potency figure is method-specific, not a generic active-content estimate. LAL endotoxin quantification is applied to the same lot, completing a two-point analytical release gate that reflects formulation-stage quality engineering rather than post-market quality correction.

Product details

Brand	Master Pharma
Active ingredient	myostine
Also known as	myostine, YK-11 SARM, Master Pharma myostine
Strength	10 mg
Form	Tabletten
Pack size	60 pieces
Item number	SARM-MYOS-MAS-002

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