Clostebol vs Andriol: Which Anabolic Steroid Reigns Supreme for Muscle Growth?

In the competitive world of bodybuilding and athletic performance, the choice of anabolic steroids can significantly impact results. Two popular contenders, Clostebol and Andriol, have sparked debates among fitness enthusiasts and professionals alike. Clostebol, known for its rapid muscle-building properties and low androgenic side effects, offers a compelling option for those seeking lean gains. On the other hand, Andriol presents a unique alternative with its testosterone derivatives, promising effective muscle growth without the harsh downsides commonly associated with steroids. But which anabolic steroid truly reigns supreme for muscle growth?

In this article, we’ll delve into the strengths and weaknesses of Clostebol and Andriol, examining their mechanisms, benefits, and potential risks. Whether you're a seasoned athlete or a newcomer, understanding these compounds can help you make informed decisions for your training regimen. Join us as we uncover which steroid may ultimately lead you to your desired physique.

Clostebol vs. Andriol: A Comparative Overview

Overview of Clostebol

Clostebol, known chemically as 4-chlorotestosterone, is a synthetic anabolic androgenic steroid (AAS) derived from testosterone. By introducing a chlorine atom at the fourth carbon position, Clostebol retains anabolic properties while significantly reducing androgenic effects. This makes it a milder alternative to more aggressive steroids like Trenbolone or Dianabol.

“Clostebol is considered a ‘mild’ steroid, offering anabolic benefits with relatively low androgenic activity, making it appealing to those concerned about hair loss, acne, or prostate enlargement.”
— Antonio, Journal of Strength and Conditioning Research

Muscle Growth and Performance Benefits

Clostebol is valued for producing lean muscle mass gains without water retention or excessive fat accumulation. It promotes:

Steady increases in strength and endurance
Faster recovery between training sessions
Lower risk of estrogen-related issues (no aromatization)
Sustainable, long-term physique improvements

Because Clostebol does not convert to estrogen, the risk of gynecomastia is virtually eliminated—an important factor for many users seeking cleaner, drier gains.

Administration and Use

Clostebol is most commonly administered via intramuscular injection (typically as Clostebol acetate) but is also available in topical formulations used medically for wound healing. Injectable versions are favored in bodybuilding for their superior bioavailability and muscle-building efficacy.

Despite its advantages, Clostebol is a banned substance in competitive sports and is classified as a controlled substance in many countries.

“Clostebol is banned in competitive sports and has resulted in high-profile doping cases due to its detection in anti-doping screenings.”
— WADA, Prohibited List

Overview of Andriol (Testosterone Undecanoate)

Andriol is a brand name for testosterone undecanoate, a long-acting testosterone ester designed for oral delivery. Unlike most oral anabolic steroids, Andriol is absorbed via the intestinal lymphatic system, bypassing the liver and minimizing hepatotoxicity.

“Testosterone undecanoate bypasses first-pass metabolism through lymphatic absorption, resulting in minimal liver strain compared to other oral steroids.”
— Basaria, New England Journal of Medicine

Benefits for Muscle and Hormonal Health

Andriol offers a unique combination of hormonal support and convenience. Its oral route appeals to individuals uncomfortable with injections, and its slow-release design promotes stable testosterone levels over time.

Key benefits include:

Enhanced muscle protein synthesis and strength
Improved libido, energy, and mood
Lower liver stress compared to traditional oral AAS
Reduced risk of estrogen spikes when used in moderation

Andriol is especially well-suited for testosterone replacement therapy (TRT) or mild anabolic support for those seeking gradual improvements in body composition.

Estrogenic and Androgenic Profile

While Andriol may convert to estrogen (due to aromatization), the steady release tends to result in fewer estrogenic side effects such as bloating or gynecomastia. That said, users with higher sensitivity may still require aromatase inhibitors (AIs) to control estradiol levels.

Similar to Clostebol, Andriol is regulated by federal and international laws and is included on WADA's banned list.

“Despite its favorable safety profile, Andriol remains a controlled substance in most regions and is banned by athletic organizations worldwide.”
— Mayo Clinic Staff, Mayo Clinic Proceedings

Final Considerations

Both Clostebol and Andriol are milder options compared to more aggressive anabolic steroids. However, they serve distinct purposes:

Clostebol is best for users prioritizing lean muscle gains with minimal water retention and a lower risk of androgenic or estrogenic side effects.
Andriol is ideal for those seeking testosterone support or gradual muscle enhancement with the convenience of oral dosing and a lower risk of liver damage.

When choosing between them, consider your:

Experience level with anabolic steroids
Tolerance to estrogen or androgenic side effects
Goals (bulking vs. maintenance)
Legal risk and access to quality compounds

Mechanism of Action: How Each Steroid Works

Understanding how Clostebol and Andriol function at the molecular level is crucial for determining their effectiveness, timing, and suitability in a performance-enhancement protocol. While both compounds promote muscle growth by enhancing anabolic activity, their mechanisms of action diverge significantly in terms of receptor binding, metabolism, and hormonal release.

Clostebol Mechanism of Action

Clostebol binds directly to androgen receptors in muscle and skeletal tissues. This binding activates a cascade of intracellular processes that increase muscle protein synthesis, accelerate tissue repair, and stimulate lean mass development.

Key actions of Clostebol include:

Direct activation of androgen receptors, stimulating anabolic gene expression
Increased muscle protein synthesis, leading to hypertrophy
Inhibition of glucocorticoid activity, which reduces muscle breakdown

“Clostebol’s 4-chloro modification suppresses its androgenic potential while preserving anabolic signaling, making it effective for muscle growth with reduced androgenic burden.”
— Saartok et al., Journal of Steroid Biochemistry

Clostebol is particularly useful in cutting or recomp phases where lean, dry muscle is the priority. Its lack of aromatization to estrogen further supports a physique that is sharp and defined, without water retention.

Andriol Mechanism of Action

Andriol (testosterone undecanoate) functions as a prodrug—meaning it becomes active after being metabolized by the body. Unlike traditional oral AAS that pass through the liver (first-pass metabolism), Andriol is absorbed through the lymphatic system, allowing for slower, more stable release of testosterone.

Once converted to active testosterone, it:

Binds to androgen receptors in muscle tissue
Promotes protein synthesis and nitrogen retention
Enhances red blood cell production, improving endurance
Supports hormonal balance and anabolic drive over time

“Testosterone undecanoate’s lymphatic absorption results in stable serum levels, making it a practical choice for TRT and steady anabolic support.”
— Zitzmann & Nieschlag, Clinical Endocrinology

While not as fast-acting or dry as Clostebol, Andriol delivers sustained anabolic support without the hormonal peaks and troughs typical of short-acting injectables. This makes it a better fit for users seeking smoother hormonal modulation and fewer side effects.

Comparative Insights

Feature	Clostebol	Andriol
Mechanism	Direct AR agonist	Prodrug → testosterone → AR agonist
Absorption Pathway	Injection/topical → bloodstream	Oral → lymphatic system → bloodstream
Speed of Action	Fast-acting	Slow, sustained release
Estrogenic Activity	None (non-aromatizing)	Moderate (aromatizable)
Muscle Growth Effect	Lean, dry gains	Steady gains with possible water retention
Use Case	Cutting, recomposition	TRT, long-term anabolic support

Both steroids enhance protein synthesis and stimulate anabolic pathways, but your ideal choice depends on your goals, side effect tolerance, and whether you prefer rapid results (Clostebol) or steady hormonal maintenance (Andriol).

Benefits of Clostebol for Muscle Growth

Clostebol is recognized for providing clean, sustainable muscle growth without the heavy side effects seen in more potent anabolic steroids. Its unique structure allows users to experience solid performance and physique benefits while minimizing water retention and estrogen-related issues.

Lean Muscle Mass Without Bloating

One of the hallmark advantages of Clostebol is its ability to promote lean muscle mass gains with minimal water retention. This makes it a go-to compound for athletes seeking a defined and sculpted physique, particularly in cutting or recomposition cycles.

Promotes dry, dense muscle development
Avoids puffiness and bloating caused by fluid retention
Ideal for stage preparation or summer body aesthetics

“The non-aromatizing nature of Clostebol minimizes fluid retention, making it a preferred choice in sports where body composition is critical.”
— Hartgens & Kuipers, Sports Medicine

Lower Risk of Androgenic Side Effects

Clostebol features a milder androgenic profile, which reduces the likelihood of issues such as:

Acne
Male pattern baldness
Excessive aggression or mood swings

Because of its gentler hormonal impact, Clostebol is sometimes used by women in performance sports with careful dosing, offering a lower risk of virilization symptoms compared to more potent compounds.

Enhanced Recovery and Endurance

Clostebol improves recovery time between training sessions by enhancing protein synthesis and reducing muscle fatigue. This allows athletes to:

Train harder and more frequently
Recover faster between workouts
Reduce the risk of overtraining

Additionally, users often report modest improvements in muscle endurance and performance, especially in short-duration, high-effort activities like resistance training and HIIT.

Benefits of Andriol for Muscle Growth

Andriol (testosterone undecanoate) offers a unique anabolic profile thanks to its oral bioavailability, lymphatic absorption, and smooth testosterone elevation. It is especially popular among those who prefer a more balanced, longer-term approach to muscle enhancement and hormone support.

Convenient Oral Delivery

Andriol’s standout feature is its oral administration, eliminating the need for injections. This makes it ideal for:

First-time users uncomfortable with needles
TRT patients or athletes seeking consistent daily testosterone support
Individuals traveling or unable to self-administer injectable steroids

The compound’s slow-release action ensures a steady elevation of testosterone without the peaks and crashes seen with shorter esters.

Low Liver Toxicity

Unlike most oral steroids, Andriol bypasses first-pass liver metabolism due to its absorption via the intestinal lymphatic system.

Reduced strain on the liver
Safer for longer-term use
Fewer hepatotoxic side effects compared to C-17 alpha alkylated orals like Superdrol or Dianabol

“Testosterone undecanoate’s lymphatic route avoids hepatic first-pass metabolism, making it one of the safest oral steroid options in terms of liver health.”
— Zitzmann & Nieschlag, Clinical Endocrinology

Stable Testosterone Elevation and Muscle Growth

Once converted to testosterone, Andriol supports:

Protein synthesis and nitrogen retention
Red blood cell production and oxygen delivery
Improved muscle recovery, strength, and training performance

Andriol also presents a lower risk of aromatization (estrogen conversion) at moderate doses, reducing the chances of gynecomastia and excessive fluid retention.

Side Effects and Risks of Clostebol

Although Clostebol is often considered a milder anabolic steroid, it still presents a range of risks that must be carefully managed. Like other exogenous androgens, its use affects the endocrine system, cardiovascular health, and may contribute to androgenic side effects in susceptible individuals.

Testosterone Suppression

Clostebol use can result in the suppression of endogenous testosterone production, a common side effect across anabolic steroids. When exogenous androgens flood the system, the hypothalamic-pituitary-gonadal (HPG) axis is suppressed, reducing or halting natural testosterone production.

Risk of hypogonadism after cycle cessation
Symptoms: fatigue, decreased libido, depression, testicular atrophy
Can take weeks to months for hormone levels to normalize

“Even low-androgenic anabolic steroids like Clostebol can suppress LH and FSH, impacting endogenous testosterone recovery.”
— Nieschlag, Endocrine Reviews

Cardiovascular Strain

Clostebol has been shown to negatively impact lipid profiles, including:

Decreased HDL (good cholesterol)
Increased LDL (bad cholesterol)
Potential elevation in blood pressure

These changes increase the risk of atherosclerosis, heart attack, and stroke, particularly with prolonged or high-dose use.

“Steroid-induced dyslipidemia is a well-documented risk factor for cardiovascular disease, regardless of the anabolic compound’s perceived mildness.”
— Thiblin et al., Cardiology Research and Practice

Androgenic Side Effects

Though Clostebol is designed to reduce androgenic activity, users may still experience:

Acne
Oily skin
Male pattern hair loss (if genetically predisposed)

In women, misuse can result in virilization, including:

Deepened voice
Facial/body hair growth
Clitoral enlargement

These symptoms are dose-dependent and may be irreversible in some cases.

Side Effects and Risks of Andriol

Andriol (testosterone undecanoate) is generally better tolerated than traditional oral anabolic steroids. However, it is still a powerful exogenous hormone that can disrupt natural systems and create hormonal imbalances.

Hormonal Suppression

As a form of exogenous testosterone, Andriol suppresses the body's own testosterone production. Over time, this can lead to testicular atrophy and hypogonadism if not managed with proper post-cycle therapy (PCT).

May result in prolonged recovery post-cycle
Symptoms include: reduced libido, low energy, poor mood, and loss of muscle

“Testosterone undecanoate administration suppresses pituitary gonadotropins and can cause long-term HPG axis disruption without PCT.”
— Bhasin et al., Journal of Clinical Endocrinology & Metabolism

Cardiovascular Impact

While less hepatotoxic than C-17 alkylated steroids, Andriol still carries cardiovascular risks, such as:

Altered lipid profile (↑ LDL, ↓ HDL)
Elevated blood pressure
Increased risk of thrombotic events

These effects are exacerbated by other risk factors such as diet, genetics, and concurrent stimulant use.

Estrogenic Side Effects

Unlike Clostebol, Andriol does aromatize into estrogen, especially at higher doses, which can lead to:

Gynecomastia (male breast tissue development)
Water retention and bloating
Emotional lability or mood swings

Aromatization risk can be managed with aromatase inhibitors (AIs), though overuse of AIs can lead to low estrogen symptoms (joint pain, libido loss, etc.).

“Testosterone therapy leads to increased estradiol levels due to aromatase activity, which can contribute to gynecomastia unless mitigated.”
— Zitzmann et al., Human Reproduction Update

Post Cycle Therapy (PCT) for Clostebol and Andriol

Following a cycle of Clostebol or Andriol, it is essential to implement a proper PCT protocol to restore natural testosterone production, rebalance hormones, and preserve lean muscle mass. Both compounds suppress the hypothalamic-pituitary-gonadal (HPG) axis, so PCT helps mitigate symptoms like fatigue, low libido, and muscle loss.

When to Start PCT

Steroid	Cycle Duration	PCT Start	PCT Length
Clostebol	6–8 weeks	3–5 days after last dose	4 weeks
Andriol	8–12 weeks	3–5 days after last dose	4–6 weeks

Recommended Swolverine PCT Stack

These supplements support testosterone production, cortisol regulation, estrogen balance, and overall recovery:

1. ZMT – All-in-One Hormonal Support

Swolverine ZMT promotes deep sleep, natural testosterone production, and recovery.

Dose: 6 capsules nightly, 30–60 minutes before bed
Key ingredients: Zinc, Magnesium, Tribulus, Ashwagandha, Fenugreek-free formulation
Benefit: Enhances testosterone, improves sleep quality, reduces cortisol

2. DHEA – Hormonal Precursor Support

Swolverine DHEA helps replenish natural androgen precursors post-cycle.

Dose: 100 mg daily, taken in the morning with food
Benefit: Supports energy, libido, and adrenal health during hormonal recovery

3. Krill Oil – Inflammation + Cardiovascular Health

Swolverine Krill Oil provides EPA, DHA, and astaxanthin for lipid profile recovery.

Dose: 2 softgels daily, with meals
Benefit: Reduces inflammation, balances HDL/LDL, supports heart and brain function

4. Greens+Reds – Micronutrient + Gut Support

Swolverine Greens+Reds helps replenish depleted micronutrients and supports digestion.

Dose: 1 scoop daily, mixed in water or a smoothie
Benefit: Improves gut health, immunity, and nutrient absorption during recovery

Optional Additions (if labs or symptoms warrant)

DIM (Diindolylmethane): To modulate estrogen if aromatization was present with Andriol
Tongkat Ali or Fadogia agrestis: For additional LH/FSH stimulation (testosterone precursors)
Bloodwork Panel: Consider post-cycle testing around Week 4 to monitor LH, FSH, Total/Free Testosterone, Estradiol, and Lipid Panel

PCT Week-By-Week Overview

Week	ZMT	DHEA	Krill Oil	Greens+Reds	Notes
1	✔ Nightly	✔ AM	✔ Daily	✔ Daily	Start immediately after cycle
2	✔ Nightly	✔ AM	✔ Daily	✔ Daily	Monitor libido & energy
3	✔ Nightly	✔ AM	✔ Daily	✔ Daily	Continue normal training
4	✔ Nightly	✔ AM	✔ Daily	✔ Daily	Optional bloodwork reassessment
5–6*	✔ (If needed)	✔ (If needed)	✔ Daily	✔ Daily	Extend PCT if using Andriol or experiencing slow recovery

*Extend to 6 weeks for longer Andriol cycles or if testosterone remains low.

Summary

A successful PCT ensures:

HPTA recovery (restart natural hormone production)
Muscle retention after Clostebol or Andriol use
Improved mood, libido, and energy
Reduced estrogen and cortisol imbalances

Pair this stack with 7–9 hours of sleep, moderate training intensity, and a high-protein, micronutrient-dense diet to optimize results.

Legal Status and Disclaimer

Legal Status of Clostebol and Andriol

Both Clostebol and Andriol (testosterone undecanoate) are classified as controlled substances in many countries due to their anabolic properties and potential for abuse.

United States

Clostebol is classified as a Schedule III controlled substance under the Anabolic Steroid Control Act, meaning it is illegal to possess, use, or distribute without a valid prescription.
Andriol, as a form of testosterone, is also a Schedule III controlled substance, requiring a prescription for legal use.

World Anti-Doping Agency (WADA)

Both compounds are listed on the WADA Prohibited List, banned in and out of competition.
Athletes who test positive for Clostebol or Andriol may face suspensions, fines, or permanent bans from professional sports.

“All exogenous anabolic androgenic steroids and their derivatives are prohibited substances in sports, regardless of route of administration.”
— WADA, Prohibited List

International Regulations

In many European, South American, and Asian countries, both Clostebol and Andriol require a prescription and are restricted substances under medical regulatory authorities.
Possession without a prescription may lead to criminal charges, fines, or confiscation by customs and law enforcement.

Medical Disclaimer

The information provided in this article is intended for educational and informational purposes only. It is not a substitute for medical advice, diagnosis, or treatment from a qualified healthcare provider.

Always consult a licensed medical professional before beginning any anabolic steroid cycle, testosterone replacement therapy, or post-cycle therapy (PCT) protocol.
The use of anabolic steroids without a prescription is illegal in many countries and may pose significant health risks.
The authors and Swolverine are not responsible for the misuse or misinterpretation of the information provided herein.
This content is not intended to encourage, promote, or endorse the use of performance-enhancing drugs (PEDs).

Comparing Clostebol and Andriol: Effectiveness and Safety

When comparing Clostebol and Andriol, it’s important to evaluate both their anabolic effectiveness and safety profiles. While both compounds promote muscle growth, they do so through different mechanisms and are suited for different user profiles based on individual goals, administration preferences, and tolerance for side effects.

Effectiveness

Clostebol is known for producing lean, dry muscle gains with minimal water retention. It binds directly to androgen receptors, which leads to rapid stimulation of anabolic activity, enhanced protein synthesis, and reduced muscle fatigue. This makes Clostebol an appealing choice for:

Competitive bodybuilders seeking a sculpted physique
Athletes looking for short-term performance boosts
Users desiring clean gains without estrogenic side effects

Because it does not aromatize, Clostebol avoids estrogen-related issues like gynecomastia and bloating. Its mild androgenic profile also makes it more tolerable for women under controlled protocols.

Andriol, by contrast, offers the benefit of oral administration and sustained testosterone release through lymphatic absorption. It steadily elevates testosterone levels, which:

Increases muscle mass and strength
Supports long-term anabolic activity
Improves red blood cell count for enhanced endurance

Its consistent hormonal release is particularly useful for TRT patients, older users, or those preferring a non-injectable format.

Safety Profile

Both compounds carry risks, but the severity and nature of those risks differ.

Risk Area	Clostebol	Andriol
Testosterone Suppression	Moderate to High	Moderate
Cardiovascular Risks	Elevated LDL / Reduced HDL	Milder but still present
Liver Toxicity	Low (injectable)	Very Low (lymphatic absorption bypasses liver)
Estrogenic Side Effects	None (non-aromatizing)	Possible (aromatizes to estrogen)
Androgenic Effects	Mild to moderate (acne, hair loss)	Low at moderate doses
Suitability for Women	Possible (low dose)	Not recommended due to estrogen conversion

“The choice of anabolic agent should align with individual risk tolerance, goals, and ability to manage side effects through PCT and lifestyle support.”
— Antonio et al., Strength and Conditioning Journal

Conclusion: Which Steroid Is Right for You?

Choosing between Clostebol and Andriol ultimately depends on your goals, administration preference, and how your body responds to hormonal shifts.

Choose Clostebol if you want:

Lean, dry gains with minimal bloat
A non-estrogenic compound for cutting or recomposition
A potentially usable compound for female athletes (under strict supervision)
Short-term physique enhancement for performance or aesthetics

Choose Andriol if you want:

Oral administration without liver toxicity
A long-term, steady testosterone replacement option
Lower risk of sharp hormonal fluctuations
Greater support for overall testosterone balance and endurance

Regardless of the compound, it’s crucial to monitor biomarkers, support cardiovascular health, and follow with a proper post-cycle therapy (PCT) plan. Working with a qualified coach or healthcare provider can help optimize results while reducing risks.

Tags: Anabolics

Previous article Next article