Sierra Metals Announces Mineral Resource Expansion at Bolivar Mine in Mexico

Additional 15.5 million copper equivalent pounds confirmed in the Dulce ore body

Toronto, August 22, 2023 - Sierra Metals Inc. (TSX: SMT) (OTC Pink: SMTSF) ("Sierra Metals" or the "Company") after systematic drilling in 2023, is pleased to announce additional 15.5 million copper equivalent ("CuEq") pounds in measured and indicated mineral resources hosted by the Dulce structure at its Bolivar mine in Mexico (Figure 1).

Ernesto Balarezo Valdez, Sierra Metals' CEO commented: "We are very pleased with the increased mineral resource announced today which is a testament to the hard work of our exploration team as we continue to demonstrate the growth potential at our Bolivar mine. This work is also consistent with our strategy of identifying additional mineral resources at our operating mines to sustain long-term production increases. And it is yet another sign of the momentum we are seeing across our business."

The results reported today include 52 drill holes from a total of 91 holes in the 2023 drill program, which increases the mineral resources when compared to those reported in the 2021 preliminary economic assessment ("PEA"). By including these new bore holes in the evaluation, the dimensions of the mineralized ore body are now extended by approximately an additional 400m, along strike by 300m vertically. The recent results in the enlarged mineralized zone, now has higher copper ("Cu") and gold ("Au") grades in comparison to average grades published in 2022 (833,058 tonnes @ 0.74 % Cu, 0.36 grams per tonne ("g/t") Au, 26.03 g/t silver ("Ag"). Additional drilling is planned for the coming months.

Notable diamond drill intercepts in the Dulce Zone:

The Company is pleased to present the results of the mineral resource update and related exploration holes drilled across the Dulce structure (see table below). The planned drilling is part of the ongoing program to replace and continuously grow mineral resources at the Bolivar mine.

Dulce Zone Mineral Resources (effective date June 30, 2023)

Dulce Zone Mineral Increase in Mineral Resources from 2021 PEA

Notes:
*Mineral resources are not ore reserves and do not have demonstrated economic viability.
*Metal prices used for the Mineral Resources calculations: Cu: 8,024.817 US$/TM, Au: 1,644.00 US$/oz, Ag: 21.44 US$/oz
*Totals have been rounded to the appropriate number of significant figures.
*Mineral resources are reported at a value per tonne (NSR) cut-off of US$25.55/t using the following unit values (US$); Cu(%): 58.435, Au(g/t): 27.009, Ag(g/t): 0.431.
*CuEq = (Au x 0.0074 + Ag x 0.4622) + Cu.
*Total Fe content has been used to correlate against density, Average Density 3.18(t/m3).

The mineralized body or "feeder zone" called Dulce strikes in a northeast - southwest trend with a 60° dip to the northwest. Its vertical projection extends from surface downwards until connecting with the mantos Bolivar NW and Cieneguita. Spatially, the Dulce zone is located between the mentioned manto bodies Bolivar NW and Cieneguita, cutting carbonate rocks previously affected by calc-silicate metasomatism. The width of mineralization varies between 0.50m and 57.30m, with the best skarn development occurring at the contact with the mantos. Copper and gold grades are directly correlated to the presence of chalcopyrite, lesser bornite, and pyrite. In addition, significant amounts of sphalerite and minor galena are present.

Figure 1: Location of the Dulce Zone at the Bolivar Mine, Mexico.

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Figure 2: Longitudinal section the Dulce structure, showing the mineralized body and its potential for increase in both directions. Black points indicate the pierce points of the diamond drilling. The mineralization coincides with a zone of low resistivity and moderate conductivity.

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Figure 3: Isometric model of the updated mineral resources. New mineral resources defined in 2023 are displayed in blue.

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Figure 4: Isometric Cu block model, Dulce structure.

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Analytical methods
Since 2022, all rock samples are prepared and analysed at the on-site assay laboratory at Piedras Verdes, Bolivar. Copper, lead, zinc and iron are analysed by acid digestion method in aqua regia, finished in Atomic Absorption. Gold is analysed by atomic absorption and finished using a fire assay test method and silver by the gravimetric finished fire test method. The diamond drilling program carried out at Bolivar is used to obtain HQ and NQ diameter drill core. The core is split in half on site, sending 50% of the core sample for analysis. Prior to 2022, rock samples were analyzed at the facilities of the commercial laboratory Chemex in Mexico.

Qualified Person
Ricardo Salazar Milla (AIG #8551), Corporate Manager - Mineral Resources, is a Qualified Person as defined in the National Instrument 43-101 - Standards of Disclosure for Mineral Projects. Mr. Salazar has reviewed and approved the scientific and technical content of this news release.

About Sierra Metals

Sierra Metals a diversified Canadian mining company with green metal exposure including increasing copper production and base metal production with precious metals by-product credits, is focused on the production and development of its Yauricocha Mine in Peru, and Bolivar Mine in Mexico. The Company is focused on safely increasing production volume and growing mineral resources. Sierra Metals has recently had several new key discoveries and still has many more exciting brownfield exploration opportunities at all three mines in Peru and Mexico that are within close proximity to the existing mines. Additionally, the Company has large land packages at all three of its mines with several prospective regional targets providing longer-term exploration upside and mineral resource growth potential.

For further information regarding Sierra Metals, please visit www.sierrametals.com or contact:

Investor Relations
Sierra Metals Inc.
Tel: +1 (416) 366-7777
Email: info@sierrametals.com

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Forward-Looking Statements
This news release contains forward-looking information within the meaning of Canadian securities legislation. Forward-looking information relates to future events or the anticipated performance of Sierra Metals and reflects management's expectations or beliefs regarding such future events and anticipated performance based on an assumed set of economic conditions and courses of action including the accuracy of the Company's current mineral resource estimates, that the Company's activities will be conducted in accordance with the Company's public statements and stated goals, and that there will be no material adverse change affecting the Company, its properties or its production estimates, the expected trends in mineral prices, inflation and currency exchange rates, that all required approvals will be obtained for the Company's business operations on acceptable terms, and that there will be no significant disruptions affecting the Company's operations. In certain cases, statements that contain forward-looking information can be identified by the use of words such as "plans", "expects", "is expected", "budget", "scheduled", "estimates", "forecasts", "intends", "anticipates", "believes" or variations of such words and phrases or statements that certain actions, events or results "may", "could", "would", "might", or "will be taken", "occur" or "be achieved" or the negative of these words or comparable terminology. Forward-looking statements include statements with respect to identifying additional mineral resources, additional drilling and plans to replace and continuously grow mineral resources . By its very nature forward-looking information involves known and unknown risks, uncertainties and other factors that may cause actual performance of Sierra Metals to be materially different from any anticipated performance expressed or implied by such forward-looking information.

Forward-looking information is subject to a variety of risks and uncertainties, which could cause actual events or results to differ from those reflected in the forward-looking information, including, without limitation, the risks described under the heading "Risk Factors" in the Company's annual information form dated March 28, 2023 for its fiscal year ended December 31, 2022 and other risks identified in the Company's filings with Canadian securities regulators, which filings are available at www.sedarplus.ca.

The risk factors referred to above are not an exhaustive list of the factors that may affect any of the Company's forward-looking information. Forward-looking information includes statements about the future and is inherently uncertain, and the Company's actual achievements or other future events or conditions may differ materially from those reflected in the forward-looking information due to a variety of risks, uncertainties and other factors. The Company's statements containing forward-looking information are based on the beliefs, expectations, and opinions of management on the date the statements are made, and the Company does not assume any obligation to update such forward-looking information if circumstances or management's beliefs, expectations or opinions should change, other than as required by applicable law. For the reasons set forth above, one should not place undue reliance on forward-looking information.

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