President Trump and top health officials heralded their drug pricing deal with Pfizer on Tuesday as a breakthrough that would save money for American patients struggling with prescription drug costs.

The reality is more complicated.

Under the deal, Pfizer agreed to charge Medicaid prices that are about the same as those it charges European countries. Trump officials also said they would push manufacturers to set prices for newly introduced drugs at similar levels in the United States and other rich countries. And they said they were planning to create a website, TrumpRx.gov, that would help people buy prescription drugs directly from manufacturers like Pfizer.

Much is still unknown about the administration’s Pfizer deal and the planned drug-buying website. Trump officials hinted that similar deals with other pharmaceutical manufacturers would follow.

But with the price equalization idea, Mr. Trump is tapping into widespread frustration that drug prices are too high in the United States. The Biden administration also took steps to try to lower drug costs for patients and the government, though it did not zero in as Mr. Trump has on the idea that drug prices are unfairly low in Europe.

The Trump administration’s changes, however, may have little if any impact for the vast majority of Americans, who fill their prescriptions for medications through health insurance.

Stacie Dusetzina, a health policy professor at Vanderbilt University who studies drug pricing, said the administration’s announcement was “a really good way to say you’re doing something about drug prices, and not actually do anything to change the underlying profits of the industry.”

Here is what we know so far.

How would aligning prices with Europe affect the cost of my drugs?

Mr. Trump’s deal with Pfizer applied to only a tiny sliver of the drugs Americans take. But it could establish a precedent for more medicines and other types of health insurance.

If the plan was expanded, the most significant savings would accrue to American employers, private insurers and government health insurance programs like Medicare, which shoulder most of Americans’ prescription costs.

In some cases, the price equalization idea could also generate direct savings for American patients. Using insurance, some patients must pay a percentage of their drug’s sticker price, say 25 percent, in the form of coinsurance. Or they have to pay the drug’s full cost until they hit up a certain annual limit — for example, $2,000.

So if a drugmaker trying to equalize its prices lowered its sticker price in the United States, or did not increase it as quickly as it otherwise would, that could mean lower out-of-pocket costs for those patients who must pay a percentage of a drug’s price.

What will Medicaid patients pay?

For at least some drugs, Pfizer’s agreement to equalize prices for Medicaid with those in Europe could generate substantial savings for state Medicaid programs, which cover low-income Americans.

But the deal will not directly benefit people on Medicaid because they already pay almost nothing in out-of-pocket costs. Federal law caps those costs at $8 per prescription for people with the lowest incomes. In some states, people with Medicaid face no out-of-pocket costs at all.

How will the TrumpRx website work?

The site will act as an entry point that will direct people to drugmakers’ websites for direct-to-consumer sales programs that manufacturers have begun announcing in recent months. The website is still under construction and is expected to go live next year.

Who are these direct-sales programs for?

A vast majority of Americans fill their prescriptions through insurance. But there are situations in which it might make sense to sidestep insurance and pay using your own money through the direct-sales programs — for example, if your doctor wants you to take a specific drug that is not covered under your insurance plan and there is no covered alternative.

For some of the direct-sales programs, like Eli Lilly’s, patients can also use insurance.

“I don’t think that they are going to help many people,” Dr. Dusetzina said, speaking of the direct-to-consumer sales programs. “There is a specific consumer who could benefit — it’s a person who has health insurance that does not cover the drug that they need, and they really need this specific branded drug.”

Which drugs will I be able to buy through TrumpRx?

Direct-to-consumer sales programs have been most widely used for the popular obesity drugs sold by Eli Lilly and Novo Nordisk, which are often not covered by insurance. In most cases, people can get them for $500 a month on the drugmakers’ websites. Eli Lilly said that in the first three months of this year, about a quarter of new prescriptions for its obesity drug, Zepbound, had been filled that way by patients using their own money.

In recent months, other manufacturers, like Bristol Myers Squibb, AstraZeneca, Novartis and Boehringer Ingelheim, have announced similar programs for drugs that are widely covered by insurance, including Eliquis, a blood thinner, and Airsupra, an asthma inhaler.

Pfizer said that when it launched its direct-sales program, it would include drugs like Duavee, used by women to reduce hot flashes; Eucrisa, for skin problems; and Toviaz, for an overactive bladder.

The products being picked for direct-sales programs have so far not included the most expensive drugs for cancer and some other illnesses, medications that can cost hundreds of thousands of dollars a year and are generally covered by insurance with some out-of-pocket costs. Buying those products directly from manufacturers, without insurance, would be unmanageable for all but the very wealthiest Americans.

Will I save money if I use TrumpRx?

Not necessarily.

Take, for example, Xeljanz, Pfizer’s widely used drug for conditions like arthritis. Pfizer said on Tuesday that it would offer Xeljanz through its direct-sales program at a 40 percent discount from the sticker price. Because Xeljanz has a sticker price of over $6,000 a month, that would work out to a self-pay price through Pfizer’s direct-sales program of more than $3,600 a month.

For most Americans, paying such prices is not feasible.

Xeljanz is already widely covered through insurance, and many insured patients already face much lower costs, in some cases only a $25 monthly co-pay.

Even with a high-deductible insurance plan, in which people are required to pay the full costs of their drugs at the start of the year until they hit a certain limit, it still might not make sense to use Pfizer’s program. GoodRx’s website, for example, showed offers on Wednesday for Xeljanz at several pharmacies in the New York City area for under $2,900 for a month’s supply.

Asked for comment on Xeljanz, Kit Longley, a spokesman for Pfizer, said the company’s focus was “working with the administration on implementing the measures announced yesterday to deliver medicines at a lower cost to American patients.”

What if the TrumpRx price is the cheapest I can find?

Even if the direct-sales price were lower than your out-of-pocket cost through insurance, it still might make sense to go through insurance.

Experts recommended that people with high-deductible plans also consider the other health-care expenses they expected for the year. If you take other drugs and are expecting to reach your out-of-pocket maximum for the year, as many people do, you are better off going through your insurance, because you were going to have to spend, say, $2,000 out of pocket for the full year no matter what.

In that scenario, “you could imagine that people could be harmed by spending this money” by buying drugs through the direct-sales programs, Dr. Dusetzina said.

How is TrumpRx different from other direct-buy websites?

There are other options for paying out of pocket for your medications instead of using your insurance.

They include GoodRx, which lists prices at pharmacies near you, or the Mark Cuban Cost Plus Drugs Company, an online pharmacy that sells hundreds of drugs.

But these tools have been most helpful in the realm of generic drugs, which are much cheaper than the brand-name products offered through the manufacturers’ direct-sales programs.

Mark Cuban’s online pharmacy, in particular, has found a niche with certain generic drugs. People save money by paying for the drugs themselves instead of using insurance in cases where pharmacy benefit managers are playing pricing games behind the scenes that drive up prices.

Should I use TrumpRx if I’m having problems with my insurance?

One way the direct-sales programs could potentially help patients is as a stopgap to be able to still get needed medications while they’re having insurance problems. It is common for patients to go without insurance coverage for a medicine for a few months while they’re fighting with their insurance over a denial.

But even in that scenario, drug pricing experts say, direct-sales programs might not be the most cost-effective option.

Instead, they recommend that you look into ways to get a drug at little or no cost through other methods.

For example, you could ask your doctor for free samples or see if you can find a cheaper way to buy your drug via tools like GoodRx or the Mark Cuban Cost Plus Drugs Company. Or you could look into whether you qualify for patient assistance programs offered by manufacturers. Your doctor might also recommend a different drug that works similarly and is covered by your insurance.