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Muscle & performance

Deca (Nandrolone Decanoate)

The classic bulk staple - slow, mild building with a joint reputation.

1 min read 16 sources

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Glass vial with pale yellow oil and a black TPD label on a white podium, next to it a glossy blue 3D steroid molecule with a long ester chain in a bright lab, symbolic image for nandrolone decanoate
Approved · since 1983

Summary

At a glance

Sources checked on 26 Oct 2026

Lean body mass in 6 months
+4.5 kg

Dialysis, randomised against placebo (+1.9 kg there), 29 participants1

More than placebo, meta-analysis
+1.59 kg

Lean soft tissue from 11 trials, no clear effect on grip strength7

New vertebral fractures in 2 years
21 %

against 43% on placebo, 65 women over 70 with osteoporosis6

Detectable in urine
6 months

Metabolites in 10 of 12 men up to 6 months after a single injection8

Raised liver enzymes
88 %

2-year trial with 17 people, the most common side effect10

  • Nandrolone decanoate is nandrolone with a long decanoate ester. It is released from the oil depot over days and acts on the androgen receptor.1316
  • After one injection the level peaked after 30 to 72 hours and the half-life was 7 to 12 days. Metabolites were partly still detectable in urine after 6 months.8
  • In randomised trials in dialysis, HIV with weight loss and in bodybuilders lean mass rose by several kilograms while fat mass mostly stayed the same.135
  • A meta-analysis of 20 trials found on average 1.59 kg more lean soft tissue than placebo, but no clear gain in grip strength and only partial gains in bone density.7
  • According to ChEMBL nandrolone decanoate has been approved since 1983. The most common side effects in a long-term trial were raised liver enzymes, acne and virilisation. Everything here is the state of research, not a recommendation.1610
Profile

Updated June 2026

How long does it stay in the body?

Share left after one dose, calculated with a half-life of ~9 days

Half-life ~9 days
After 18 days: 25 %
Day 9 · 50 %Day 18 · 25 %Day 27 · 12.5 %Day 45 · 3.1 %

Simplified model without an absorption phase, half-life from the TPD lexicon. The lexicon gives 6 to 12 days, we calculate with the middle.

Class
19-nor anabolic

long decanoate ester

Use
Intramuscular or subcutaneous

1-2x per week

Half-life
about 6-12 days
WADA
banned

anabolic

Sizes
5 sizes

200mg/ml, 300mg/ml, 433mg/ml …

Contents 13 sections
  1. At a glance
  2. What is Deca?
  3. How it works
  4. Use and dosing
  5. What the research shows
  6. Research status
  7. Side effects
  8. Storage
  9. PCT / after coming off
  10. Related compounds
  11. FAQ
  12. Glossary
  13. Sources

What is Deca?

Deca (Nandrolone Decanoate) is one of the oldest and best-known anabolics - a 19-nor steroid with a long decanoate ester. It builds slowly and comparatively mildly and is known for the reputation of making joints feel "smoother". Clinically it was used for muscle wasting, anemia and osteoporosis.

This information is for research and educational purposes only. No medical advice.

Comparison

Nandrolone with short and long esters

The same compound at the same receptor with esters of different length, as stated in the TPD lexicon. Tap a card to open its entry.

Short ester NPP (Nandrolone Phenylpropionate) AR Mix of both esters NandroMix 300 AR
Long ester Deca (Nandrolone Decanoate) AR
Testosterone, long ester Testosterone Enanthate AR

In a direct comparison the level with the short phenylpropionate ester peaked earlier and higher than with decanoate. 9

How it works

Nandrolone activates the androgen receptor, aromatizes only weakly (less estrogen than testosterone), but - like all 19-nor compounds - has progesterone activity. That is the reason for the prolactin-related nickname "deca dick" (libido/erection issues) when prolactin is not controlled.

Where it acts

Where nandrolone decanoate acted in trials

Tap a point or a card. All effects observed in human trials.

  1. Skeletal muscle

    Lean mass rose, on average 1.59 kg more than on placebo7

    Observed in trials
  2. Bone

    Bone density rose, fewer new vertebral fractures in osteoporosis6

    Observed in trials
  3. Blood

    Haemoglobin rose by 14.3% over 2 years6

    Observed in trials
  4. Liver

    Raised liver enzymes in 88% in a 2-year trial10

    Observed in trials
  5. Skin

    Acne in 59% in the same trial10

    Observed in trials
  6. Testes and hormone axis

    Own testosterone suppressed, longest after a small injection into the glute9

    Observed in trials

Targets in the ChEMBL database16

Compound CHEMBL1200946: one recorded mechanism, agonist with direct binding to the human receptor.

Androgen receptor
Gene
AR
UniProt
P10275
ChEMBL
CHEMBL1871
Action
Agonist, direct binding
Glossy blue 3D steroid molecules dock onto glowing binding sites on light blue muscle fibres, a transparent joint on the right
Nandrolone binds to the androgen receptor. Symbolic image.

Use and dosing

Dosing

Dosing, titration and syringe

Loading the dosing information …

  • Getting started and stepping up, drawn as a staircase
  • Units on the U-100 syringe for every step
  • How long one vial lasts
Glass vial with pale yellow oil and a black TPD label, next to it a disposable syringe with a blue needle cap on a white lab bench
Symbolic image.

What the research shows

Nandrolone decanoate has an unusually good clinical data base compared to other anabolics. The Johansen study (JAMA, 1999) showed a significant gain in fat-free mass on nandrolone vs placebo in dialysis patients. The AAS pharmacology is summarized in Kicman (2008).

Study results

What the trials measured

Interactive: switch tabs, tap points, show or hide arms. Arms are named relative to each other, no dosing advice.

Gain in lean body mass14352

Change in kg from baseline, randomised trials

Dialysis1 29 people, 6 months
Placebo +1.9 kg
Nandrolone decanoate +4.5 kg
HIV, men with weight loss4 12 weeks
Placebo +0.4 kg
Nandrolone decanoate +1.6 kg
HIV, women with weight loss3 38 women, 12 weeks
Nandrolone decanoate +3.5 kg
Bodybuilders5 16 men, 8 weeks
Nandrolone decanoate +3.5 kg
Dialysis with and without training2 79 people, 12 weeks
Nandrolone decanoate +3.1 kg

Where there is only one bar the abstract gives no placebo value, according to the trials the gain there was clearly smaller. Bodybuilders: from 59.54 to 63.06 kg, rounded. The meta-analysis of 20 trials found 1.59 kg more than placebo.

Older women with osteoporosis6

65 women over 70, two years, all with calcium

New vertebral fractures6 Share over 2 years
Placebo 43.0%
Nandrolone decanoate 21.0%
Lumbar spine bone density6 Increase after 2 years
Nandrolone decanoate 3.7%
Femoral neck bone density6 Increase after 2 years
Nandrolone decanoate 4.7%
Haemoglobin6 Increase after 2 years
Nandrolone decanoate 14.3%

The increases are given against baseline. Compared with placebo, bone density at the femoral neck and trochanter and haemoglobin were significantly higher. The meta-analysis saw a clear effect only for the total hip.

Telomeres and blood formation10

Share of evaluable people, one group over 2 years

Longer telomeres10 after 12 months, 10 of 13
All participants (no placebo) 77%
Longer telomeres10 after 24 months, 10 of 10
All participants (no placebo) 100%
Blood count improved10 after 12 months, 8 of 16
All participants (no placebo) 50%
Blood count improved10 after 24 months, 10 of 16
All participants (no placebo) 63%

Rare inherited disorders with too short telomeres and impaired blood formation, 17 people, no placebo. Two people died of lung failure during the trial.

Row of test tubes with clear liquid, a transparent model of a knee joint on the right in a bright lab
Trials range from dialysis and osteoporosis to rehabilitation after hip fracture. Symbolic image.

Research status

Where the research stands

Trials on the registry that explicitly name nandrolone decanoate. As of 26 Oct 2026. 15

  1. Preclinical Binding to the androgen receptor in muscle and prostate (rat, rabbit)
  2. Phase 1 no registered trial
  3. Phase 2 3 trials, 2 completed
  4. Phase 3 no registered trial
  5. Approval since 1983
Approved: ChEMBL lists nandrolone decanoate with phase 4 as the highest phase and first approval in 1983.16
Show all 6 trials on a timelineHide timeline 5 completed 1 running 2 with results
Phase 2
Without phase

Bar: start to primary endpoint (planned for running trials). Green = completed, blue = progress until 26 Oct 2026.

Side effects

  • Prolactin: "deca dick" - libido/erection issues, cabergoline as countermeasure.
  • HPTA suppression: strong and long-acting - longer PCT needed.
  • Estrogen: weak aromatization, an AI may still be needed.
  • Water retention, blood pressure.

Tolerability

Frequency in the 2-year trial

Out of 100 participants, how many had the event over 2 years. One group of 17 people, no placebo.

88 of 100 All participants (no placebo)
Event All participants (no placebo)
Raised liver enzymes10 88%
Acne10 59%
Virilisation10 59%

No event of grade 4 or higher. In a small trial after hip fracture there were 10 adverse reactions on nandrolone and 8 on placebo.1011

Storage

Store the oil solution at room temperature, protected from light - no fridge needed. Out of reach of children.

Four glass vials with golden oil on a white shelf, next to them a folded light blue cloth
Oil solution at room temperature and protected from light, no fridge needed. Symbolic image.

Related

Related compounds

Same receptors or blends with Deca (Nandrolone Decanoate): all in the TPD lexicon.

Deca (Nandrolone Decanoate)
NPP (Nandrolone Phenylpropionate) The same nandrolone, short ester NandroMix 300 Contains nandrolone decanoate plus phenylpropionate Test/Deca Mix 500 Contains nandrolone decanoate plus testosterone enanthate Testosterone Enanthate Testosterone with a long ester Trenbolone Enanthate Another 19-nor steroid, long ester Equipoise (Boldenone Undecylenate) Another steroid with a very long ester

FAQ

Common questions about Deca (Nandrolone Decanoate)

Short answers, each backed by the sources below.

How long does one injection last?

In a study of healthy men the nandrolone level peaked 30 to 72 hours after a single injection and the terminal half-life was 7 to 12 days. In another study smaller oil volumes into the glute gave the highest availability. Metabolites were still detectable in the urine of 10 of 12 men up to 6 months later.89

Is nandrolone decanoate approved?

Yes. The ChEMBL database lists nandrolone decanoate as an approved drug with first approval in 1983. ClinicalTrials.gov still lists trials, among them on age-related muscle loss and telomere disorders. Everything here is the state of research, not a recommendation.1615

What do the trials show on muscle mass?

In dialysis lean mass rose by 4.5 kg in 6 months (placebo 1.9 kg), walking and stair climbing became faster. In HIV with weight loss women gained 3.5 kg of lean mass in 12 weeks, men 1.6 kg against 0.4 kg on placebo. Bodybuilders gained about 3.5 kg in 8 weeks, mostly in the trunk and legs. Grip strength did not change in the dialysis trial.1345

What does the 2026 meta-analysis say?

It pools 20 randomised trials against placebo. Lean soft tissue rose by 1.59 kg on average, fat mass, grip strength and knee extension strength did not change clearly and for bone density only the total hip improved. The authors rate the certainty of evidence as low and advise against routine clinical use.7

What happens to the body's own hormone production?

Nandrolone from outside suppresses the body's own testosterone production. In a comparison study suppression was fastest but brief after the short phenylpropionate ester and lasted longest after a small decanoate injection into the glute. Reviews describe that the suppression can last for months after stopping.914

Which side effects were seen?

In a 2-year trial with 17 people 88 percent had raised liver enzymes and 59 percent each had acne and signs of virilisation, no side effect reached grade 4. Reviews of anabolic steroids add falling HDL cholesterol and rising blood pressure. In a small trial after hip fracture there were 10 adverse reactions on nandrolone and 8 on placebo.101411

Why is nandrolone detectable in sport for so long?

The long ester releases nandrolone over weeks and the metabolites 19-norandrosterone and 19-noretiocholanolone appear in urine. After a single injection they were found in 10 of 12 men up to 6 months later. In 5 of 37 men they were detectable in small amounts even before the study.8

Glossary

Terms explained briefly

Dotted words in the text open these explanations directly.

19-nor steroid
Steroid lacking the methyl group at carbon 19. Nandrolone and trenbolone belong to this group.
Androgen receptor
Protein inside the cell that androgens bind to. Genes are then read, for example for muscle building.
Bone density
Mineral content of bone, measured by X-ray (DEXA). Low values mean a higher fracture risk.
Decanoate ester
Long fatty acid chain on nandrolone. It makes it oil-soluble and releases it slowly from the depot.
Depot
The oil solution stays in the tissue after the injection and releases the compound over days.
Hormone axis (HPTA)
Hypothalamus, pituitary and testes together control the body's own testosterone production. Androgens from outside suppress this axis.
Lean body mass
Body weight without fat: muscle, bone, organs and water.
Meta-analysis
Statistical summary of several studies on the same question.
Placebo
Dummy preparation without active substance. Comparing against it shows what is due to the substance itself.
Telomeres
Protective caps at the ends of chromosomes. If they are too short, blood formation can be impaired.

Practice

PCT / after coming off

Anabolic substances suppress the body's own testosterone production in the research context. Anyone who comes off a cycle (rather than running it continuously) typically uses a post-cycle therapy (PCT) to restart the natural axis (HPTA).

The standard scheme in the research/literature context combines a SERM (tamoxifen and/or clomifene, alternatively enclomiphene) over roughly four weeks, optionally preceded by HCG to re-sensitise the testes before the SERM block. An aromatase inhibitor (anastrozole/exemestane) belongs more to on-cycle estrogen control than to the PCT itself.

19-nor note: nandrolone and trenbolone are progestagenic and can raise prolactin. The literature additionally discusses a prolactin-lowering agent (cabergoline) and a somewhat longer wash-out window here.

Tip: order the PCT items together with the cycle so they are already on hand when you come off.

This information serves research and educational purposes only. Not medical advice.

Tamoxifen (Nolvadex) SERM, core of PCT View Clomid (Clomifen) SERM, core of PCT View Enclomiphene (Androxal) SERM alternative View HCG testicular restart before PCT View Arimidex (Anastrozole) aromatase inhibitor, on-cycle View Aromasin (Exemestane) aromatase inhibitor, on-cycle View Cabergoline prolactin control for 19-nor View

Evidence

Sources

Show all 16 sourcesHide sources 14 Studies1 Trial registry1 Database checked 26 Oct 2026

Studies

  1. Nandrolone decanoate in dialysis, randomised against placebo

    Johansen et al., JAMA, 1999

    DOI 10.1001/jama.281.14.1275 PMID 10208142
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  2. Strength training and nandrolone in dialysis

    Johansen et al., Journal of the American Society of Nephrology, 2006

    DOI 10.1681/ASN.2006010034 PMID 16825332
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  3. Women with HIV and weight loss

    Mulligan et al., Archives of Internal Medicine, 2005

    DOI 10.1001/archinte.165.5.578 PMID 15767536
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  4. Men with HIV and weight loss, compared with growth hormone

    Storer et al., Journal of Clinical Endocrinology and Metabolism, 2005

    DOI 10.1210/jc.2005-0275 PMID 15914526
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  5. Bodybuilders: body composition after 8 weeks

    Hartgens et al., International Journal of Sports Medicine, 2001

    DOI 10.1055/s-2001-18679 PMID 11354529
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  6. Older women with osteoporosis, two years against placebo

    Frisoli et al., Journals of Gerontology Series A, 2005

    DOI 10.1093/gerona/60.5.648 PMID 15972619
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  7. Meta-analysis: muscle strength, body composition and bone density

    Prokopidis et al., Journal of Cachexia, Sarcopenia and Muscle, 2026

    DOI 10.1002/jcsm.70276 PMID 41936385
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  8. Levels and urine detection after one injection

    Bagchus et al., Journal of Clinical Endocrinology and Metabolism, 2005

    DOI 10.1210/jc.2004-1526 PMID 15713722
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  9. Nandrolone esters compared: ester, injection site and oil volume

    Minto et al., Journal of Pharmacology and Experimental Therapeutics, 1997

    DOI 10.1016/s0022-3565(24)36598-x PMID 9103484
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed (Titel, Datensatz ohne DOI)
  10. Telomere disorders: telomeres, blood count and side effects over 2 years

    Clé et al., Haematologica, 2023

    DOI 10.3324/haematol.2022.281808 PMID 36579443 NCT02055456
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  11. Pilot trial on rehabilitation after hip fracture

    Hulsbæk et al., BMC Geriatrics, 2021

    DOI 10.1186/s12877-021-02273-z PMID 34016037 NCT03545347
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  12. Binding of anabolic steroids to the androgen receptor in muscle and prostate

    Saartok et al., Endocrinology, 1984

    DOI 10.1210/endo-114-6-2100 PMID 6539197
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  13. Review of the pharmacology of anabolic steroids

    Kicman, British Journal of Pharmacology, 2008

    DOI 10.1038/bjp.2008.165 PMID 18500378
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed
  14. Review: effects and side effects of anabolic steroids in athletes

    Hartgens und Kuipers, Sports Medicine, 2004

    DOI 10.2165/00007256-200434080-00003 PMID 15248788
    Checked 26 Oct 2026 via doi.org, Crossref, PubMed

Trial registry

  1. All trials on ClinicalTrials.gov

    ClinicalTrials.gov, U.S. National Library of Medicine

    Checked 26 Oct 2026 via ClinicalTrials.gov API v2

Database

  1. Mechanism and approval in ChEMBL

    ChEMBL, EMBL-EBI (CHEMBL1200946)

    Checked 26 Oct 2026 via ChEMBL

In the shop

Deca (Nandrolone Decanoate) in the catalog

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