Sildenafil / Tadalafil / Oxytocin

Chewable Tablet

55 mg / 20 mg / 125 U

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Product Overview

Sildenafil Description1-3  

Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor with a half-life of about 4 hours. Clinically, it is used for erectile dysfunction and pulmonary hypertension. Due to its half-life, sildenafil is typically taken “on-demand” before sexual activity.

Tadalafil Description4-6 

Tadalafil, also a phosphodiesterase type 5 (PDE5) inhibitor, has a mean terminal half-life exceeding 17 hours, significantly longer than other medications in this class. This prolonged half-life supports both once-daily use and on-demand dosing. Tadalafil is indicated for pulmonary arterial hypertension (PAH), erectile dysfunction (ED), benign prostatic hypertrophy (BPH), and for patients requiring treatment for both ED and BPH simultaneously.

Oxytocin Description7-12

Oxytocin is a hormone produced in the hypothalamus and stored in the posterior pituitary gland. A synthetic form is available and functions the same as naturally occurring oxytocin. It stimulates smooth muscle contractions in the uterus during labor and promotes milk ejection through its action on the alveolar ducts after milk is formed. Because of these uterine effects, oxytocin has been used for labor induction, assistance with placental delivery, and management of postpartum bleeding. Oxytocin has also been linked to social bonding, mood-related effects, and aspects of sexual function.

Sildenafil1-3 

Phosphodiesterase (PDE) has many isoforms and is an enzyme that has many functions in the body including degrading the effect of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). PDE5 is an enzyme that is found in many parts of the body including in the smooth muscle of the corpus cavernosum, prostate, bladder, the vascular and visceral smooth muscle, skeletal muscle, urethra, platelets, kidney, lung, cerebellum, heart, liver, testis, seminal vesicle, and pancreas. Sildenafil is structurally similar to cGMP and prevents degradation of cGMP by competitively binding and inhibiting activity of PDE5. When PDE5 is inhibited, cGMP accumulates and leads to smooth muscle relaxation. In the corpus cavernosum, this leads to penile erection. In the pulmonary system, it leads to vasodilation in the pulmonary arteries.

Tadalafil4-6 

Phosphodiesterase (PDE) has many isoforms and is an enzyme that has many functions in the body including degrading the effect of cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). PDE5 is an enzyme that is found in many parts of the body including in the smooth muscle of the corpus cavernosum, prostate, bladder, the vascular and visceral smooth muscle, skeletal muscle, urethra, platelets, kidney, lung, cerebellum, heart, liver, testis, seminal vesicle, and pancreas. Tadalafil is a selective inhibitor of PDE5, the enzyme responsible for the degradation of cGMP. The drug has selective activity on PDE5 than other phosphodiesterase isoforms. Tadalafil activity on PDE5 is more than 10,000-fold more than for PDE1, PDE2, PDE4, and PDE7 enzymes. Increased cGMP leads to smooth muscle relaxation in the corpus cavernosum which can help in maintaining an erection.

Oxytocin7-12

Oxytocin causes G-protein coupled receptors to increase intracellular calcium which leads to uterine contraction. The stimulation of uterine contractions causes more oxytocin to be released. As more oxytocin is released it positively influences even more release of oxytocin. This release of oxytocin is called positive feedback which is much different than how many hormones work in the endocrine system. Oxytocin administered exogenously causes the same response as endogenously produced oxytocin. Not only does oxytocin stimulate uterine contractions, but it also causes contractions of myoepithelial cells in the alveolar ducts found in female breast tissue. These contractions force milk from these ducts into even larger sinuses, which subsequently enables milk expulsion. When a baby attempts to latch onto the mother’s breast it causes oxytocin secretion into the blood in the same manner as vaginal delivery; instead of uterine contractions, milk is ejected from the breast. Similar to the actions of oxytocin in the uterus to stimulate contractions during delivery, milk-ejection from breast tissue occurs due to positive feedback. In the brain, it is proposed that oxytocin stimulates social and sexual function by its activity in many areas of the brain including its activity on neurotransmitters.

Sildenafil1,2

Common   

  • Headache
  • Flushing
  • Dyspepsia
  • Nasal congestion
  • Dizziness

 

Tadalafil4,5

Common 

  • Headache
  • Dyspepsia
  • Flushing
  • Back pain and myalgia (typically delayed onset, resolving within 48 hours)
  • Nasal congestion
  • Pain in limbs

 

Oxytocin7-9

Common

  • Loss of appetite
  • Nausea, vomiting
  • Stomach pain.

Contraindications & Precautions1,2,4,5,7-9

Sildenafil  

Contraindications:  

  • Known intolerance or hypersensitivity to sildenafil or tablet excipients
  • Use of nitrates and alpha-blockers due to risk of life-threatening hypotension

Precautions:  

  • Use with caution in patients with:
  • Severe hepatic impairment (Child-Pugh Class C)
  • Severe renal impairment (creatinine clearance <30 mL/min)
  • History of NAION (non-arteritic anterior ischemic optic neuropathy)
  • Recent history of myocardial infarction, stroke, or unstable angina

 

Tadalafil

Contraindications

  • Known intolerance or hypersensitivity to tadalafil or tablet excipients
  • Use of nitrates and guanylate cyclase (GC) stimulators therapy, such as riociguat due to risk of life-threatening hypotension

Precautions

  • Use with caution in patients with:
  • Severe hepatic impairment (Child-Pugh Class C)
  • Severe renal impairment (creatinine clearance <30 mL/min)
  • Retinitis pigmentosa (rare inherited retinal disorder)

 

Oxytocin

Contraindications

  • Known intolerance or hypersensitivity to oxytocin
  • Pregnancy

Precautions

  • Oxytocin may possess antidiuretic effects—extended administration may increase risk of fluid overload
  • Cardiovascular disease, due to oxytocin’s potential vasopressor effects
  • History of NAION (non-arteritic anterior ischemic optic neuropathy)
  • Recent history of myocardial infarction, stroke, or unstable angina
  • Store at controlled room temperature (20°C to 25°C / 68°F to 77°F)
  • Protect from moisture and light
  • Keep in a tightly closed container
  1. Sildenafil Prescribing Information – Pfizer. www.accessdata.fda.gov/drugsatfda_docs/label/2011/021368s20s21lbl.pdf Revised March 2014. Accessed May 31, 2025
  2. Clinical Pharmacology Sildenafil clinical monograph 2025 https://www.clinicalkey.com/pharmacology/
  3. Smith BP, Babos M. Sildenafil. [Updated 2023 Feb 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558978/  Accessed August 20, 2025
  4. Tadalafil Prescribing Information – Eli Lilly. www.accessdata.fda.gov/drugsatfda_docs/label/2011/021368s20s21lbl.pdf Revised October 2011. Accessed May 31, 2025
  5. Clinical Pharmacology Tadalafil clinical monograph 2025 https://www.clinicalkey.com/pharmacology/
  6. Padda IS, Tripp J. Phosphodiesterase Inhibitors. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559276/ Accessed August 20, 2025
  7. Oxytocin Prescribing Information – Fresenius Kabi. https://www.accessdata.fda.gov/drugsatfda_docs/label/2022/018248s049lbl.pdf Revised September 2022. Accessed May 31, 2025
  8. Clinical Pharmacology Oxytocin clinical monograph 2025 https://www.clinicalkey.com/pharmacology/
  9. Osilla EV, Patel P, Sharma S. Oxytocin. [Updated 2025 Feb 15]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK507848/
  10. Kou J, Lan C, Zhang Y, Wang Q, Zhou F, Zhao Z, Montag C, Yao S, Becker B, Kendrick KM. In the nose or on the tongue? Contrasting motivational effects of oral and intranasal oxytocin on arousal and reward during social processing. Transl Psychiatry. 2021 Feb 4;11(1):94.
  11. Zhuang Q, Zheng X, Yao S, Zhao W, Becker B, Xu X, Kendrick KM. Oral Administration of Oxytocin, Like Intranasal Administration, Decreases Top-Down Social Attention. Int J Neuropsychopharmacol. 2022 Nov 17;25(11):912-923.
  12. Quintana DS, Glaser BD, Kang H, Kildal ESM, Audunsdottir K, Sartorius AM, Barth C. The interplay of oxytocin and sex hormones. Neurosci Biobehav Rev. 2024 Aug;163:105765.

WPPL operates as a 503A compounding pharmacy and prepares individualized prescription medications pursuant to provider direction. Compounded preparations are not reviewed, tested, or approved by the FDA.

This listing also includes commercially manufactured products for convenience; these items are not compounded by our pharmacy and are sold as provided by their manufacturers. Any statements regarding non-compounded products are manufacturer-supplied, have not been evaluated by the FDA, and are not intended to diagnose, treat, cure, or prevent any disease. WPPL does not verify or endorse any therapeutic claims made by manufacturers. Please refer to original labeling for complete product information.

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