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Tadalafil vs. Cialis: differences, dosages, costs

12 min read

Written by: 

Patricia Weiser, PharmD

Reviewed by: 

Raagini Yedidi, MD

Updated:  Apr 04, 2025

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Reviewed By

Raagini Yedidi, MD

Raagini Yedidi, MD, is an internal medicine resident and medical reviewer for Ro.

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Key takeaways

  • Tadalafil is the generic version of brand-name Cialis, and is the drug’s active ingredient. Tadalafil and Cialis work in the same way to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). 

  • Generic tadalafil is cheaper than brand-name Cialis. 

  • While tadalafil and Cialis share an identical active ingredient, some people may experience slight variations in side effects or effectiveness, potentially due to differences in inactive ingredients used in generics. However, these differences are generally minimal and don’t affect the overall results for most people.

Here's what we'll cover

Here's what we'll cover

Key takeaways

  • Tadalafil is the generic version of brand-name Cialis, and is the drug’s active ingredient. Tadalafil and Cialis work in the same way to treat erectile dysfunction (ED) and benign prostatic hyperplasia (BPH). 

  • Generic tadalafil is cheaper than brand-name Cialis. 

  • While tadalafil and Cialis share an identical active ingredient, some people may experience slight variations in side effects or effectiveness, potentially due to differences in inactive ingredients used in generics. However, these differences are generally minimal and don’t affect the overall results for most people.

"Is tadalafil the same as Cialis?" This is a common question, especially since tadalafil is the second-most-prescribed medication for erectile dysfunction (ED) after sildenafil (Viagra). Tadalafil is the generic version of Cialis, a widely used treatment for both erectile dysfunction (ED) and benign prostatic hyperplasia (BPH, or enlarged prostate). But, what exactly sets them apart? 

In this article, we'll dive into the similarities and differences between tadalafil vs. Cialis, including their effectiveness, cost, side effects, and more.

Cialis Important Safety Information: Read more about serious warnings and safety info.

Viagra Important Safety Information: Read more about serious warnings and safety info.

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Tadalafil vs. Cialis: what’s the difference? 

The main difference is that Cialis is a brand-name medication, while tadalafil is the generic version, as well as the name of Cialis’s active ingredient.

Cialis, made by Eli Lilly, was first approved by the FDA in 2003. Before generic Cialis was available, the brand-name version, Cialis, was a go-to option for treating ED, and was the first alternative to Viagra. Then, in 2018, after Eli Lilly’s patent ended in the United States, generic tadalafil was approved and became widely available. Today, FDA-approved generic tadalafil products are made by numerous generic drug companies, such as Teva, Accord, Amneal, Aurobindo, Cipla, Lupin, Watson, Zydus, and many others.

The table below summarizes how tadalafil and Cialis are alike and different:

Tadalafil (generic)

Cialis (brand)

Form and appearance

Form: Oral tablet

Appearance: Varies with manufacturer. No standard shape or color.

Form: Oral tablet

Appearance: Yellow, film-coated, almond-shaped tablets with the letter “C” and strength imprinted.

Year of FDA approval or availability: 

2018

2003

Drug class

PDE5 inhibitor

PDE5 inhibitor

Dosage strengths

2.5 mg, 5 mg, 10 mg, 20 mg

2.5 mg, 5 mg, 10 mg, 20 mg

How fast does it kick in?

30 minutes to 2 hours

30 minutes to 2 hours

How long does it last?

36 hours

36 hours

Common side effects

Headache, indigestion, back pain, muscle pain, nasal congestion, flushing, pain in arms or legs

Headache, indigestion, back pain, muscle pain, nasal congestion, flushing, pain in arms or legs

Cost

Less expensive

Example: 

Tadalafil 5 mg (30 tablets) costs around $29 with GoodRx discount.

Drug costs vary with dose, quantity, pharmacy, insurance/discounts, and location. 

More expensive

Example:

Cialis 5 mg (30 tablets) costs around $315 with GoodRx discount.

Drug costs vary with dose, quantity, pharmacy, insurance/discounts, and location. 

Generic vs. brand name drugs

So, what’s the difference between brand name vs. generic drugs? It has much to do with the development and approval process, regulated by the US Food and Drug Administration (FDA).

For brand-name drugs, the process starts with extensive research and development. Pharmaceutical companies spend years conducting laboratory testing and clinical trials to prove their drug is safe and effective. This process can take many years and costs a lot of money. Once the drug is approved by the FDA, the company gets a patent, which gives them exclusive rights to sell it for a set period. During this time, the price tends to be higher to help cover all the costs that went into developing the drug.

For generic drugs, the process is a bit faster and simpler. Since generics are usually copies of brand-name drugs, they don’t need to go through all the same clinical trials. Instead, generic manufacturers just need to show that their generic version is "bioequivalent" to the original. This means they must have studies proving that the generic drug delivers the same amount of the same active ingredient to the bloodstream as the brand-name version, and that it works the same way in the body. 

The generic companies also have to meet the same manufacturing standards, showing they can make the drug properly and consistently, ensuring each batch meets quality standards. Once the FDA reviews and approves the generic, it can be sold at a much lower price, since the company doesn’t have to cover all the same research and development costs that the brand-name company did. 

What is tadalafil (generic Cialis), and how does it work?

Before we explain how tadalafil works, let’s start with understanding the erection process. An erection happens when blood flows into the penis during sexual arousal. This is made possible by the relaxation of blood vessels and smooth muscle in the penis. The process starts when nerve cells release a substance called nitric oxide, which helps produce a compound called cGMP in the smooth muscle. cGMP causes the muscles to relax, letting more blood flow into the penis. 

Once the penis is erect, it stays firm, as long as the smooth muscle in the penis stays relaxed and the veins that normally drain blood out of the penis are compressed. However, when an enzyme called PDE5 breaks down cGMP, the muscle tightens again, and the erection ends. If something goes wrong with any of these steps, it can lead to erectile dysfunction (ED). This can happen from time to time to anyone with a penis, but if it’s happening often and affecting your quality of life, it may be time to consider trying a medication like tadalafil.

Tadalafil is a phosphodiesterase type 5 inhibitor (aka PDE5 inhibitor), a class of prescription medications that includes other popular drugs like Viagra (sildenafil). Tadalafil works by blocking the PDE5 enzyme, which increases the amount of cGMP in the body. This relaxes the blood vessels, improving blood flow to the penis. Like other drugs in its class, tadalafil only works when you’re sexually stimulated—because that’s what triggers the release of nitric oxide to kick off the erection process.

Tadalafil is primarily used for treating ED, allowing men to achieve and maintain an erection long enough for satisfying sexual activity. Besides ED,  tadalafil is also prescribed for reducing signs and symptoms of BPH, a condition also known as enlarged prostate. Men who have both ED and BPH may be prescribed daily tadalafil to treat both conditions at once.

Tadalafil is also the active ingredient in several different brand-name medications that are used to treat pulmonary arterial hypertension (PAH), a condition that causes high blood pressure in the lungs. These FDA-approved medications for PAH work by increasing blood flow to the lungs and reducing strain on the heart. Examples include:

  • Tadliq, an oral liquid suspension

  • Adcirca, an oral tablet

  • Alyq, an oral tablet

  • Opsynvi, an oral tablet that combines tadalafil and macitentan, another medication for PAH

Brand-name Cialis and generic versions of Cialis are not approved for PAH. 

What is Cialis, and how does it work? 

Cialis is the brand-name version of tadalafil. It works the same way as generic tadalafil by blocking the PDE5 enzyme to increase blood flow to the penis, which makes it easier to get and maintain an erection. Cialis, like its generic counterpart, is approved for use in men to treat ED, BPH, or both. 

Is tadalafil the same as Cialis? 

Tadalafil and Cialis contain identical active ingredients, but they are not 100% the same. The primary difference lies in branding and formulation. Cialis is a brand-name product of tadalafil, developed by Eli Lilly. Cialis underwent clinical trials and was approved by the FDA in 2003. 

Generic tadalafil was approved in 2018, after the brand patent expired. As explained above, generic drugmakers need to prove that their product works the same in the body and meets the same high-quality standards, but they aren’t required to go through the same clinical trial and approval process as brand-name drugs. All of the clinical information in official FDA labeling for generic tadalafil, such as the recommended dosage, side effects, warnings, and clinical trial results, is just a copy of the Cialis labeling, aka prescribing information. 

Although generics are meant to work the same as brand-name drugs, there can be some differences in their formulation. The "inactive" ingredients in a generic don’t have to be the same as the brand-name version. Even small changes in these ingredients can affect how the medication works and lead to unexpected side effects. Some people might have trouble with certain ingredients, like lactose, gluten, or dyes. The look, taste, allergens, and shelf life of a generic may also vary because of differences in how the active ingredient is used in the formula.

For most people and medications, switching to a generic is a way to get the same benefits at a lower cost, with no issues. In fact, in the US, more than 70% of prescriptions are filled with generic drugs. 

Currently, tadalafil is manufactured by multiple generic drug companies, which makes it available for a lower price, but these may contain different inactive ingredients (such as fillers, binders, and dyes). To illustrate, here’s a comparison of the ingredients in brand-name Cialis, made by Eli Lilly, versus a generic version, made by Aurobindo Pharmain, as described in each drug’s labeling:

  • Cialis ingredients: Each tablet contains tadalafil and the following inactive ingredients: croscarmellose sodium, hydroxypropyl cellulose, hypromellose, iron oxide, lactose monohydrate, magnesium stearate, microcrystalline cellulose, sodium lauryl sulfate, talc, titanium dioxide, and triacetin.

  • Tadalafil ingredients: Each tablet contains tadalafil and the following inactive ingredients: colloidal silicon dioxide, copovidone, croscarmellose sodium, hypromellose, lactose monohydrate, magnesium stearate, microcrystalline cellulose, polyoxyl 40 hydrogenated castor oil, talc, titanium dioxide, triacetin, and yellow iron oxide.

As you can see, the inactive ingredients are similar, but not exactly the same. 

Is tadalafil as good as Cialis?

Tadalafil is the active ingredient in Cialis and is considered just as effective, as required by the FDA for all generic medications. 

However, some people say in anecdotal reports that they notice a difference when switching from Cialis to generic tadalafil. While many find that generic tadalafil works just as well, others feel that it isn’t as strong or that it causes different side effects. These differences could be coincidental. Or, in some cases, it could be the result of different inactive ingredients, which can vary between brand-name and generic drugs. 

If you switch from Cialis to generic tadalafil and notice a difference in side effects or results, speak with your healthcare provider, as they may adjust your dosage if needed. Or, your pharmacist may be able to refill your prescription with a different generic tadalafil product, made by a different manufacturer. 

Filling your prescription at a reputable pharmacy is important to ensure you’re getting a reliable product. Unfortunately, counterfeit versions of popular medications like Cialis and Viagra are not uncommon. These fake drugs can look similar to the real thing, but they may not contain the correct active ingredients or could be dangerous, causing unexpected side effects or even harm.

To protect yourself, always fill your prescriptions at licensed pharmacies, whether it’s a local one or an online service. Look for pharmacies that are accredited by the National Association of Boards of Pharmacy (NABP) and have state licensing in place. Be cautious of online “pharmacies” that offer extremely low prices or don’t require a prescription—these could be signs of counterfeit products. If you’re ever unsure, ask your healthcare provider for recommendations on trusted pharmacies.

Tadalafil vs. Cialis: doses and dosage schedules 

Both tadalafil and Cialis are available as 2.5 mg, 5 mg, 10 mg, and 20 mg oral tablets. The recommended dosage is the same for both brand Cialis and generic tadalafil. The dosage depends on how and why it’s prescribed, among other factors, as follows:

  • For as-needed use for ED, the recommended starting dose is typically 10 mg, taken before anticipated sexual activity. Depending on your response and tolerance, your provider may increase your dose up to 20 mg or lower it to 5 mg. The maximum is one dose per day. 

  • For daily use for ED, the recommended dosage is 2.5 mg or 5 mg taken once per day regardless of sexual activity. This daily dosing regimen is often preferred by people who want a more spontaneous approach to ED management. 

  • For treating BPH, or concurrent ED and BPH, the standard dosage is 5 mg once daily. In some cases, it may be prescribed along with another medication for BPH, such as finasteride (Proscar). 

A lower dosage may be prescribed for individuals with kidney problems, liver problems, and those taking certain medications that can interact. Be sure to follow the dosing instructions from your healthcare provider. 

Cialis and tadalafil may be taken with or without food. Unlike sildenafil, the timing and fat content of your meals do not affect Cialis or tadalafil. Swallow the tablet whole; do not split or crush it, as doing so may cause it to work less effectively.

Some companies offer other forms of tadalafil. Ro offers the following products:

  • Ro Sparks. This tablet is an as-needed treatment option for ED. It contains a blend of tadalafil (the same active ingredient as Cialis) and sildenafil (the active ingredient in Viagra). It dissolves under your tongue over several minutes and kicks in  around 15 minutes after it dissolves, and keeps you ready to go for up to 36 hours.

  • Daily Rise Gummies: This gummy contains 7 of mg tadalafil, the same active ingredient as Cialis. You take it once a day, and it can be used to manage ED, BPH, or both. 

Note that Ro Sparks and Daily Rise Gummies are compounded medications in forms that are not FDA-approved, though their active ingredients are FDA-approved for treating ED. Compounded drugs are permitted under federal law under certain circumstances. You need a prescription to get either one, if considered safe and appropriate by a licensed healthcare provider.

Tadalafil vs. Cialis: side effects 

The reported side effects for tadalafil and Cialis are identical, and the majority of people aren’t too bothered by these side effects. Here are the most common tadalafil side effects, according to studies of Cialis:

  • Headache

  • Indigestion

  • Back pain

  • Muscle pain

  • Nasal congestion

  • Flushing

  • Arm or leg pain

While rare, Cialis or tadalafil can cause serious side effects like a painful erection that lasts longer than 4 hours (called priapism)and, in very rare cases, sudden vision or hearing loss. It's important to seek emergency medical attention if you experience any unusual side effects.

Cialis and tadalafil aren’t safe for everyone, especially people with certain heart conditions, and may cause dangerous interactions. Always share your medical history and everything you take with your prescriber so they can help make sure it’s safe for you to take ED medications like Cialis or tadalafil.

So, are there any differences in side effects of tadalafil vs Cialis? Since tadalafil and Cialis have the same active ingredient, their side effects should be identical. However, some people report different experiences when switching between them.

Anecdotally, some Reddit users say Cialis feels stronger, with more noticeable side effects like facial flushing, while certain generic tadalafil products seem milder. But there isn’t any scientific evidence to back up any of these claims.

It’s possible that differences in results with tadalafil vs. Cialis may be due to different inactive ingredients, which can affect absorption or tolerability. Some people may be sensitive to certain dyes or fillers used as inactive ingredients. If you notice unexpected changes, talk to your healthcare provider to see if a different generic or dose might work better for you.

Tadalafil vs. Cialis: cost 

Cost is one of the most noticeable differences between brand Cialis and generic tadalafil. Tadalafil tends to be the more affordable option. 

Of course, costs with and without insurance can vary depending on the dose, quantity, the pharmacy you use, your location, and any available discounts. As an example, though: 

  • You can get 30 tablets of tadalafil 5 mg for around $29 with a GoodRx discount. 

  • On the other hand, Cialis 5 mg (the brand-name version) is significantly more expensive, costing about $315 for 30 tablets with a GoodRx discount. 

If you have insurance, coverage for tadalafil and Cialis will depend on your specific plan. Some insurance providers cover tadalafil but may exclude brand-name Cialis or ED treatments altogether. It’s a good idea to check with your insurance company to see what’s covered and whether there’s a difference in copays between the brand and generic versions.

If affordability is a concern, Eli Lilly offers Lilly Cares, a nonprofit program that provides eligible individuals with a 12-month supply of Cialis at no cost. You can visit the Lilly Cares website or talk to your healthcare provider to find out if you qualify.

As mentioned, you may also be able to save money through discount cards, such as GoodRx or SingleCare, at many pharmacies. Before picking up your prescription, it’s worth exploring these options to find the best price.

Tadalafil vs. Cialis: appearance 

Since Cialis was developed and patented by one company, Eli Lilly, it has a uniform appearance and formulation. It’s a yellow, smooth, almond-shaped tablet with the letter “C” and strength clearly marked on it. Each strength is a slightly different shade of yellow and is imprinted as follows:

  • 2.5 mg tablets: “C 2 1/2”

  • 5 mg tablets: “C 5”

  • 10 mg tablets: “C 10”

  • 20 mg tablets: “C 20”

While brand name Cialis tablets are always yellow and almond-shaped, generic tadalafil does not have a standardized appearance. Since tadalafil is  available in generic form and produced by different manufacturers, the tablets can vary in shape, size, and color. However, regardless of how the pills look, they work the same way as Cialis because they contain the same active ingredient (tadalafil).

Tadalafil vs. Cialis: which is better for ED? 

Tadalafil and Cialis are equally effective at treating erectile dysfunction. The biggest difference between the two is the cost. Cialis is more expensive, while generic tadalafil offers the same benefits at a much lower price. 

However, some people prefer the consistency of a brand-name medication like Cialis, which has been around for longer and has a well-known reputation. Ultimately, the best choice depends on your personal preference and what works best for your budget.

Tadalafil vs. Cialis vs. other ED meds

When comparing tadalafil and Cialis to other ED medications, like Viagra (sildenafil), there are a few key differences. For one, tadalafil and Cialis last much longer—up to 36 hours—while Viagra and sildenafil typically only last around four hours. This extended duration makes tadalafil and Cialis better options for those who want more flexibility.

You may be wondering if tadalafil is stronger than Viagra. The answer depends on what you’re looking for. If you want a short-acting, on-demand option for ED, Viagra may be better for you. But, tadalafil’s longer 36-hour duration of action or daily dosing option (and bonus efficacy for BPH) might make it a better choice for some people.  

All PDE5 medications approved for ED work the same way to increase blood flow to the penis, and all of them are proven safe and effective. Ultimately, it comes down to individual needs and response, as different medications may work better for different people and have different side effect profiles.

Bottom line: tadalafil vs. Cialis

Tadalafil is the generic version of Cialis. While these medication names are often used interchangeably, many people wonder whether there are meaningful differences between them. Here’s a recap of what we’ve covered in this article: 

  • Tadalafil is the active ingredient in Cialis and is considered just as effective for treating ED. Generic tadalafil and brand-name Cialis have the same active ingredient: tadalafil, which means they are essentially the same in terms of what they do in the body and how well they work for ED.

  • Tadalafil is less expensive than Cialis. Brand-name medications, including Cialis, are typically more expensive than generic medications. If you're looking for a cost-effective option, tadalafil does the job just as well. However, if you prefer the brand-name consistency of Cialis, you should expect to pay more for it. 

  • There are other differences, such as inactive ingredients. Other differences between tadalafil vs. Cialis are the pill appearance, available strengths, and inactive ingredients. While side effects are generally similar, some people may notice slight differences due to the inactive ingredients.

Frequently asked questions (FAQs)

DISCLAIMER

If you have any medical questions or concerns, please talk to your healthcare provider. The articles on Health Guide are underpinned by peer-reviewed research and information drawn from medical societies and governmental agencies. However, they are not a substitute for professional medical advice, diagnosis, or treatment.

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